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Article by Barbara Driscoll and Marcia Warren
Dune Savers – Grassroots Conservation Sunset Beach is situated in the municipality of Treasure Island in Pinellas County, west of Tampa. It boasts some of the area’s iconic beaches and is a haven for tourism. Beach dunes and native coastal plantings in this barrier island village captured the attention of native plant enthusiasts, including some members of the Pinellas Chapter of the Florida Native Plant Society. A group of concerned volunteers began to maintain native plants in local beach access parking lots. They also noticed non-native plants competing with native plants such as sea oats (Uniola paniculata), dune sunflower (Helianthus debilis), and railroad vine (Ipomoea pes-caprae) on the adjacent dune system. They were aware that non-native ornamental plants do not hold back erosion or provide ecological services like native plants do, and the spread of non-native plants could dominate the dunes if left unchecked. This could endanger the substantial public investment made during previous Treasure Island dune restoration projects. Volunteers took action to prevent further degradation of the important dune system, and
in cooperation with the City of Treasure Island, the group’s knowledge and efforts became key in helping conserve the city’s beloved beach plantings and dunes. Once invasive plants were removed, the volume of native dune plants increased to fill in the gaps. After two years of commitment, the group now known as the ‘Dune Savers’ continues to make a positive impact. As curious beach goers walk by, they often
stop and ask questions. Dune Savers volunteers educate them about native plants, how to keep the dunes sustainable, and how to make better landscape plant choices. Dune Savers volunteers also participate in the city event known as ‘Treasure the Island Day’. There, visitors can learn about the Dune Savers projects, view other educational exhibits, and take home native plants donated by Wise Hands Native Nursery. CONTINUED ON PAGE 14
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Article by Barbara Driscoll and Marcia Warren
Article by Dr. Warren G. Abrahamson
Article by Craig Huegel
Article by Roger L. Hammer
https://instagram.com/floridanativeplantsociety/ https://linkedin.com/company/8016136 https://twitter.com/fl_native_plant
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Article by Dr. Warren G. Abrahamson Photos by Drs. James Cronin, György Csóka, and Warren Abrahamson
Oaks Have a Lot of Gall: The Intimate Interactions of Oaks and Gall Wasps This is a story about the interactions of oaks and herbivorous gall-inducing wasps. To set the stage, let’s first explore the diversity of oaks and oak gall wasps. Oak Diversity The genus Quercus (oaks) of the beech family (Fagaceae) is both species-rich and evolutionarily and ecologically diverse. With ≈ 600 species worldwide, there are > 435 oaks distributed across temperate and tropical regions of the northern hemisphere. The Flora of North America, which describes native and naturalized plants found in North America north of Mexico, includes 92 oak species placed in five sections of the subgenus Quercus, the subgenus centered on the Americas. A second oak subgenus, Cerris, includes oaks native to the Old World (Denk et al. 2017, Nixon 2024). Oaks are the predominant tree in many eastern U.S. forests and are especially dominant in southeastern forests. The Flora of the Southeastern United States lists 53 oak species, several with multiple varieties (Weakley and the SE Flora Team 2023). The Atlas of Florida Plants lists 26 oak species plus hybrids (Wunderlin et al. 2024) with representatives from three of the five sections of the subgenus Quercus. Section Lobatae includes red oaks (e.g., Q. myrtifolia, Q. laevis), Section Quercus includes white oaks (e.g., Q. chapmanii, Q. stellata), and Section Virentes includes live oaks (e.g., Q. virginiana, Q. geminata). Florida’s oak species “ecologically sort” into vegetative communities along environmental gradients of soil moisture, nutrient availability, and fire regime (Cavender-Bares et al. 2004). For example, Q. myrtifolia, Q. geminata, and Q. chapmanii share traits that facilitate their success in xeric, fire-prone habitats like oak scrub while traits of Q. virginiana, Q. laurifolia, and Q. nigra generate preference for mesic environments such as hammocks. The success of oaks across a wide range of environments is, in part, due to their “plastic” drought responses which allow oaks to acclimate their physiology (e.g., via modifications to their gas exchange and moisture loss) and growth according to water availability (Kaproth et al. 2023). Gall-inducing Organisms and Gall Wasps Organisms that induce plant galls are phylogenetically and ecologically diverse, spread across four kingdoms, two phyla, two arthropod classes, and six insect orders. Gall-inducing arthropods occur among mites, thrips, aphids, moths, and weevils but the greatest species richness and the most complex ●
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galls occur among flies and wasps. Gall midges (i.e., flies) and gall wasps account for ≈ 70% of all North American arthropod galls. Given the diversity of gall inducers, it is surprising that few plant groups account for most galls. More than 90% occur on dicots and most of these are on members of only three plant families: Asteraceae (aster, goldenrod), Fagaceae (beech, oak), and Rosaceae (rose, blackberry) (Abrahamson and Weis 1987).
Galls are remarkable structures produced by the intimate interaction of two unrelated organisms (Figure 1). Gall inducers stimulate their hostplant and the plant’s reactions generate a unique gall from the interaction of the two genomes. From the gall-inducer’s perspective, the gall provides some protection from the elements and natural enemies, and importantly, galls provide nutrition for the developing larvae. From the plant’s perspective, galls and the organisms within represent a drain on their energy and nutrient budgets (Abrahamson and Weis 1987). The restriction of galls to a limited number of plant families suggests that appreciable barriers make host shifts to unrelated plant groups evolutionarily difficult. The gall-wasp family (Cynipidae) includes ≈ 1,400 species organized across 12 tribes. Of these tribes, the oak gall-wasp tribe (Cynipini, which occurs primarily in the northern hemisphere) is the most speciose with > 1,000 species (Nieves-Aldrey ●
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et al. 2021). Many species have life cycles that alternate unisexual generations of all females with bisexual generations. Because both the females and galls of the unisexual and bisexual generations differ morphologically and can occur on different hostplants, the alternate generations of numerous species are described as separate species. Fortunately, phylogenetics coupled with morphological studies are clarifying cynipid taxonomy.
beetles, and wasps. While many inquilines coexist with the gall wasp and have little to no impact on the wasp, others are “lethal” inquilines that kill the gall wasp by crowding it or consuming it as it feeds on gall tissue. Parasitoids are insect parasites that feed on their insect host, eventually killing it. There are ≈ 200 known parasitoids of oak gall wasps, all of which are wasps that attack only oak gall wasps. Because parasitoids attack their hosts by inserting their eggs through gall tissues and into the gall-inducing larvae, gall traits like toughness, wall thickness, size, and timing of appearance and maturity affect rates of parasitism. Despite the gall’s protective traits, parasitoids inflict considerable mortality to oak gall wasps. Opportunistic predators of oak gall wasps include insects, mammals, and birds. Hornets can extract and consume wasp larvae from soft galls like those on leaves; mice can prey on oak galls; and birds (e.g., chickadees, woodpeckers, and nuthatches) can generate substantial mortality to oak gall wasps. Because some galls (e.g., certain stem galls) persist long after oak gall wasps emerge, such galls often become shelters for ants, solitary bees, and predatory wasps (Csóka et al. 2005). Clearly, cynipid oak galls are biodiversity micro “hot spots.”
Natural Enemies of Gall Wasps: Inquilines, Parasitoids, and Predators Just as oak galls provide shelter and nutrition for the gall inducer, oak galls are potential shelter and food resources for other organisms including those that are obligate gall inhabitants and others that opportunistically associate with galls (Csóka et al. 2005). Obligate inhabitants include inquiline and parasitoid insects. Numerous inquilines (i.e., insects that exploit the living places of another animal) are associated with wasp galls including representatives from four insect orders: flies, moths,
Interactions of Oaks and Gall Wasps Our surveys of oak wasp galls in Pennsylvania, North Carolina, and Florida recorded > 245 gall-wasp species with 130 species documented on 25 oak species in Florida. Galls occur on roots, flowers (catkins), acorns, buds, and most commonly on stems and leaves (Figures 2-4). At Archbold Biological Station (hereafter “Archbold”) near Lake Placid, Florida, detailed surveys of six oak species found 88 gall-wasp species. Quercus myrtifolia had the highest gall-wasp richness and diversity with 37 species, followed by Q. chapmanii
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(28), Q. inopina (17), Q. laevis (16), Q. geminata (12), and Q. minima (10) (Price et al. 2004). Florida and especially Florida’s scrub-oak vegetation are oak gall biodiversity “hot spots.” Florida has more oak gallwasp species than any country in Europe and North Africa, and its fauna is almost as speciose as the entire oak gall fauna of the western Palearctic. Even though California is nearly 2.9X larger in area and has more topographic variation than Florida, it has only 15% more species (≈ 150 spp.). The six oak species at Archbold represent < 25% of Florida’s oak species, yet they host 68% of the oak gall-wasp species in Florida (Price et al. 2004). A key finding of our surveys was the fidelity of gall wasps to a single oak species or a cluster of closely related oak species (Figure 5-6). This specificity is, in part, a consequence of the required intimate relationship between gall inducers and their hostplants. Gall inducers must stimulate appropriate reactions from their host to produce a functional gall, otherwise they perish. Oak gall wasps can discriminate among closely related oaks, even between hybrids and their parental oaks in hybrid zones (Aquilar and Boecklen 1992). The consequence is oak species have sets of gall-wasp communities that overlap or not with communities on other oaks depending on the evolutionary relatedness of the oaks. Oak gall wasps have such narrow and specific hostplant associations that naturalists who know oak galls can use the presence of oak galls to confirm the identity of an oak (Abrahamson et al. 1998). Several factors including oak architecture influence the occurrence of gall wasps. The abundance of many gall wasps, but not all, is positively related to oak tree size (Abrahamson et al. 1998, Cronin et al. 2020). Larger oaks have greater architectural complexity, and they may be easier to colonize. Females of a given species oviposit their eggs on a specific hostplant organ (e.g., stem or leaf) and have individual ovipo-
sition phenologies (Figures 2-6). A consequence of such differences is the reduction of competition among wasp species via “niche-space partitioning.” For example, no gall wasp that attacked a member or members of the white oak section ever attacked a member of the red oak section and vice versa. The evolution of gall wasps involves specialization with resultant divergence of hostplant exploitation. Gall-wasp occurrence is also influenced by the primary and secondary chemistry of oaks (Abrahamson et al. 2003). Six oaks (three red oaks, two live oaks, and one white oak) examined at Archbold differed in levels of tannins, phenolics, lignin, cellulose, hemicellulose, and nitrogen, but not carbon. These differences are strongly correlated with the occurrence of the gall-wasp communities associated with each oak species. That both primary and secondary metabolites correlate with gall-wasp occurrence suggests the importance of these metabolites, or correlated but unmeasured compounds, to female host choice and/or offspring performance and survival. The highly specific gall-wasp communities associated with oaks begs the question of whether similarities and differences among gall-wasp communities reflect the phylogeny of oak species. In other words, do evolutionarily related oaks have more similar gall-wasp communities? Indeed, they do! The red oak, white oak, and live oak sections have been separated evolutionarily for > 40 Ma (Manos and Hipp 2021), so it is not surprising that oak gall-wasp communities of the red oak, white oak and live oak sections are unique from one another. The gall-wasp communities on closely related oaks like the red oaks Q. rubra, Q. velutina, and Q. coccinea show remarkable similarity and overlap, as do the wasp communities on the white oaks Q. alba and Q. montana (Abrahamson et al. 1998). There are many parallels between oak phylogeny and clustering of gall-wasp communities. Yet, the match is not perfect. Oak genetics show the live oaks Q. virginiana, Q.
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geminata, and Q. minima are closely related. The high degree of similarity of gall-wasp communities on Q. virginiana and Q. geminata also suggests their close relationship but the less similar gall-wasp community on Q. minima suggests a more distant relationship than does oak genetics. The reason is likely confounding variables such as differences in plant architecture, phenology, physiology, or geographic range. For example, Q. minima’s small stature and typically unbranched growth form offer little architectural complexity for oak gall wasps, resulting in limited gall-wasp diversity. Disturbance Influences and Conservation Natural and anthropogenic disturbances (e.g., droughts, fires, highways) generate a myriad of impacts to natural communities. Fire is a recurrent disturbance in many ecosystems worldwide that influences the evolution of organisms and the composition of fire-prone communities (Abrahamson et al. 2021). We know a good deal about how fire impacts plant communities, but we know far less about fire’s effects on insect herbivores and higher trophic levels. Intense fires can eradicate sedentary herbivores like gall insects, which then require recolonization from unburned sites to reassemble gall wasp and natural-enemy communities. To better understand how fire impacts oak gall communities, we quantified gall abundance, richness, and diversity on four oaks (Q. geminata, Q. chapmanii, Q. inopina, and Q. myrtifolia) at replicated sites varying from 1.5 to 91 years since fire. Each sampled site that was < 19 years since fire experienced a high-intensity fire that extirpated gall wasps (Cronin et al. 2020). As we expected, gall abundance was positively correlated with tree height and with increasing time-since-fire. Colonization was rapid, 14 of 23 sampled cynipid species were recorded within 3 years of fire, and 21 cynipid species at 7 years after fire. Oak gall-wasp richness and diversity became asymptotic within ≈ 7 years. Available hostplant material or plant architecture is one of the drivers in gall-wasp community recovery given that time-since-fire was significantly related to gall abundance only when oak height was excluded from the analysis. Land managers are increasingly using fire management plans that rely on prescription burning to manage firedependent habitats (Abrahamson et al. 2021). The goals of such plans include enhancing plant richness and diversity, improving habitat conditions for species of special concern, and reducing fuel loads. Recolonization of burned sites by gall-inducing insects depends on the availability of insects from unburned sources and the availability of appropriate host tissues (Cronin et al. 2020). Extensive natural communities like those at Archbold are composed of a mosaic of patches with differing burn histories, which enables colonization of intensely burned sites by gall wasps from nearby lightly burned or unburned areas. Under such conditions, reassembly of oak gall communities is rapid and frequent fires are unlikely to negatively affect gall wasps or their natural enemies. However, we suspect that gall-wasp community reassembly will be slower and may only partially reestablish in isolated, small oak fragments that are now common on Florida’s sand ridges. Investigations focused on the effects of fragment ●
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isolation and size, burn history and intensity, and cynipid dispersal abilities on oak gall-wasp community assembly will inform natural-area conservation and management. Abrahamson, W.G., and A.E. Weis. 1987. Nutritional ecology of arthropod gall makers. In: Slansky, F. Jr., and J.G. Rodriguez (eds.) Nutritional ecology of insects, mites, and spiders. John Wiley & Sons, Inc. pp. 235-258. Abrahamson, W.G., C.R. Abrahamson, and M.A. Keller. 2021. Lessons from four decades of monitoring vegetation and fire: maintaining diversity and resilience in Florida’s uplands. Ecological Monographs 91: e01444. https://doi.org/10.1002/ecm.1444. Abrahamson, W.G., M.D. Hunter, G. Melika, and P.W. Price. 2003. Cynipid gall-wasp communities correlate with oak chemistry. Journal of Chemical Ecology 29: 209-223. Abrahamson, W.G., G. Melika, R. Scrafford, and G. Csóka. 1998. Gall-inducing insects provide insights into plant systematics relationships. American Journal of Botany 85: 1159-1165. Aguilar, J.M., and W.J. Boecklen. 1992. Patterns of herbivory in the Quercus grisea × Quercus gambelii species complex. Oikos 64: 498-504. Cavender-Bares, J., K. Kitajima, and F.A. Bazzaz. 2004. Multiple trait associations in relation to habitat differentiation among 17 Floridian oak species. Ecological Monographs 74: 635-662. Cronin, J.T., G. Melika, and W.G. Abrahamson. 2020. Time-since fire and cynipid gall wasp assemblages on oaks. Biodiversity and Conservation 29: 1177-1203. https://doi.org/10.1007/ s10531-020-01930-w. Csóka, G., G.N. Stone, and G. Melika. 2005. Biology, ecology, and evolution of gall-inducing Cynipidae. In: Raman, A., C.W. Schaefer, and T.M. Withers (eds.) Biology, ecology, and evolution of gall-inducing arthropods. Science Publishers, Inc. pp. 573-642. Denk, T., G.W. Grimm, P.S. Manos, M. Deng, and A.L. Hipp. 2017. An updated infrageneric classification of the oaks: review of previous taxonomic schemes and synthesis of evolutionary patterns. In: Gil-Pelegrín, E., J.J. Peguero-Pina, and D. Sancho-Knapik (eds.). Oaks physiological ecology. Exploring the functional diversity of genus Quercus L. Tree Physiology 7. doi:10.1007/978-3-319-69099-5_2. ISBN 978-3-319-69099-5. Kaproth, M.A., B.W. Fredericksen, A. Gonzalez-Rodriguez, A.L. Hipp, and J. Cavender-Bares. 2023. Drought response strategies are coupled with leaf habit in 35 evergreen and deciduous oak (Quercus) species across a climatic gradient in the Americas. New Phytologist 239: 888–904. https://doi.org/10.1111/nph.19019. Manos, P.S., and A.L. Hipp. 2021. An updated infrageneric classification of the North American oaks (Quercus subgenus Quercus): review of the contribution of phylogenomic data to biogeography and species diversity. Forests 12: 786. https://doi.org/10.3390/f12060786. Nieves-Aldrey, J.L., J.A. Nicholls, C-T. Tang, G. Melika, G.N. Stone, J. Pujade-Villar, M. Buffington, Y. Maldonado, & E. Medianero. 2021. Re-description and systematic re-appraisal of the genus Kokkocynips Pujade-Villar & Melika, (Hymenoptera: Cynipidae: Cynipini), including new combinations of Nearctic species and the description of a new species from Panama. Zootaxa 4938: 205-232. https://doi.org/10.11646/zootaxa.4938.2.3. Nixon, K.C. 2024. Quercus. In: Flora of North America editorial committee (eds.) 1993+. Flora of North America North of Mexico [Online]. 25+ vols. New York and Oxford. Vol. 3. http://beta. floranorthamerica.org/Quercus. Accessed [1/24/2024]. Price, P.W., W.G. Abrahamson, M.D. Hunter, and G. Melika. 2004. Using gall wasps on oaks to test broad ecological concepts. Conservation Biology 18: 1405-1416. Weakley, A.S., and SE Flora Team. 2023. Flora of the southeastern United States. https:// fsus.ncbg.unc.edu/. Accessed [1/24/2024]. Wunderlin, R.P., B.F. Hansen, A.R. Franck, and F.B. Essig. 2024. Atlas of Florida plants http:// florida.plantatlas.usf.edu/. Accessed [1/24/2024].
Dr. Warren Abrahamson is a Research Associate of Archbold Biological Station and Professor of Biology Emeritus at Bucknell University. An evolutionary ecologist, his research includes the ecology of saw and scrub palmettos, studies of Florida vegetation and fire, and the multi-trophic level interactions of hostplants (goldenrods and oaks), gall insects, and natural enemies.
I am deeply grateful to George Melika, whose taxonomic studies of North American oak gall wasps made our studies possible. I thank Chris Abrahamson, Mark Deyrup, Jim Cronin, Peter Price, György Csóka, Jill Abrahamson, Rob Scrafford, Mark Hunter, John Fitzpatrick, Hilary Swain, Eric Menges, Linda Gette, Vivienne Sclater, Kevin Main, Tim Craig, Joanne Itami, and many Bucknell University students for their help. Archbold Biological Station, Bucknell University, and the National Science Foundation supported our studies.
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Article by Craig Huegel, PhD
Symphyotrichum Asters for the Home Landscape Part 1: Species That Sucker Aggressively The true asters, members of the genus Symphyotrichum, are a rich and diverse group. In Florida, 29 species have been vouchered and the majority are beautiful and significant additions to any landscape designed for pollinators. Every member of this genus, as well as other genera in the Family Asteraceae, have evolved specifically to be pollinated by insects. Aster flower anatomy is complicated. What we see as single, daisy-like flowers are actually head-like structures known as capitula. These are composed of large numbers of individual flowers. In some species, the capitulum is composed of outer rows of ray flowers that may look like petals. These are not fertile and do not produce seeds – their only function is to attract pollinators. The central part of the capitula is composed of disk flowers, which are fertile. These open from the center of the disk and proceed outward, each opening for only a couple of days. To minimize self-pollination, the male parts (stamens) normally protrude out of each disk flower on different days than the female parts (pistils). In this way, pollen from one disk flower is deposited on the stigma of a different disk flower and severe inbreeding is avoided. A few members of the Asteraceae like rayless sunflower (Helianthus radula), skip ray flowers completely and rely on the lure of their disk flowers to get pollinated. Ray flowers are an ingenious evolutionary construct – they persist throughout the opening and closing of the disk flowers that may last weeks. There is an elegant economy in only having to produce a pollinator lure once each flowering season. Because of their flower structure, asters offer large amounts of pollen and nectar in a very small space for days to weeks. Pollinators can gather what they need without a lot of flying around and that makes their efforts safer and more energy efficient. Asters are the ultimate pollinator seducer, but pollinators are richly rewarded by this seduction. This ●
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system obviously is effective as there are many aster species worldwide. The other aspect of Symphyotrichum asters that is so beneficial is their blooming season. Most flower in the late summer to early fall, but a few wait even longer and provide pollen and nectar at a time when virtually nothing else is available. By prolonging the flowering season, food is available and abundant for pollinators that have not yet retired for the winter. Symphyotrichum asters also serve as the host plant for the pearl crescent butterfly. My admiration for asters evolved from my love of butterflies and my desire to create gardens to attract them. Over time, I learned what was required of a true pollinator garden and I embraced the needs of more than butterflies. When I began gardening in Florida 35 years ago and searched for wildflowers, I found that only three members of Symphyotrichum were regularly being propagated and sold here. That began my quest to find others, to propagate them, add them to my home landscape, and to see more of these species made available to the public. Of course, nurseries can only grow species they can sell. It is up to the rest of us to ask for and then purchase these plants when a nurseryperson decides to propagate something new. Some Symphyotrichum asters sucker aggressively while others are better behaved. Suckering asters are poor choices for small landscapes where diversity is important. They will overrun a small planting bed and overtake the more-diminutive members of a planting. They are excellent choices, however, for expansive areas where they can form large colonies and fill in what might otherwise be barren soil. This article divides asters into those that tend to sucker and form extensive colonies over time (Part 1) and those that seem more demure (Part 2). Some of this behavior depends on growing conditions. Wetland asters will not sucker as aggres-
sively in soils that don’t stay moist and asters adapted to full sun will not grow the same as they normally would if kept partly shaded. These are my experiences, and yours may differ. I have chosen not to include the various saltmarsh species native to Florida as they have limited use in most typical home landscapes. Symphyotrichum asters are sometimes confusing to identify. Except in extreme South Florida, they die back to the ground in the winter and reemerge again in the spring. This is a good time to identify most of them as they vary in the characteristics of their basal leaves. As these lower leaves mature, look at their size and shape, whether they have teeth along the leaf margins and whether the undersides are shiny or have hairs – either on the leaf veins, the entire lower leaf surface or on both sides of the leaf surface. Symphyotrichum asters have leaves without petioles (the leaf stem) – what is known as sessile, and they tend to alternate along the main stem that arises from the basal leaf cluster as the summer progresses. Look closely at these leaves too in order to help with identification. Do they get smaller as they go up ●
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the stem or change shape? We often rely on flowers to confirm identification, but is not always easy since the vast majority of Symphyotrichum asters have ray flowers that are some shade of lavender and yellow central disk flowers. Many also exhibit some degree of color variability. Nevertheless, flower color, flower size, and the shape of the ray flowers can often help with identification. Last, look at the plant community the aster is growing in. There are wetland species as well as upland ones. Carolina aster (Symphyotrichum carolinianum) Carolina aster is ubiquitous throughout Florida in wet to moist soils. It also is the aster most widely propagated by native plant nurseries. As part of natural communities, it occurs most widely along river banks, the edges of ponds and other wet depressions. In a landscape, it can be pushed to survive in average soils, though it will never thrive without supplemental irrigation. Unlike other members of this genus, Carolina aster does not spread by suckering as much as it spreads by vining and through its copious production of seed. Partly because of its differing nature, some taxonomists have placed it in a monotypic genus/species (Ampelaster carolinianus), though this is not currently accepted by all. In much of its range, Carolina aster dies back significantly in the winter, but it roars back in spring, sending its partly woody stems in all directions up to nearly a dozen feet from its main stem, and rambling through the adjacent vegetation. Its leaves are simple, alternate and narrowly oval and about 1-2 inches long. Carolina aster is most beloved because of its large number of highly fragrant blooms in the late fall. These are composed of many extremely thin ray flowers surrounding a central yellow disk. This aster may best be grown on a fence or trellis in a home landscape, though it is quite attractive if you have a spot where it can ramble through a hedge. Elliott’s aster (Symphyotrichum elliottii) Elliott’s aster occurs throughout Florida except in the western Panhandle and the Florida Keys. It is found in wet soil habitats such as roadside ditches and depressional marshes. This is a very robust ●
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species. Though it dies back to the ground each winter, it emerges in the early spring and quickly grows to 4-6 feet in height. Its smooth stems support toothed sessile leaves that can be 6-9 inches long and up to 2 inches wide. All of these traits make it easy to identify in the field as no other native aster is this tall and stout. Blooming occurs in late fall and is spectacular. Huge numbers of highly fragrant lavender flowers are produced atop each stem. Each is composed of pinkish lavender ray flowers surrounding a yellow disk. Though Elliott’s aster is extremely showy when in bloom, it is also very aggressive and its large size overwhelms most other species it may occur with. Use it only along pond and wetland edges where a monoculture of asters is desired.
White oldfield aster (Symphyotrichum pilosum) As its name implies, white oldfield aster occurs in a variety of open upland habitats throughout its extensive range in North America. In Florida, it has been reported primarily in the western and central Panhandle though it also is vouchered from Marion County. I first saw ●
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this species in the front yard of friends near Tallahassee where it formed a significant clump of white-flowered herbaceous stems along the side of their house. I have since used it this way in my Pasco County landscape and it has thrived. White oldfield aster is an herbaceous perennial that dies back to the ground in winter and reemerges again in spring. Its thin wiry stems can reach 3 feet tall, and individual plants can be 3-4 feet across. The slightly hairy upright stems often turn reddish brown as they mature. It has alternate sessile elliptical leaves that are up to about 4 inches long near the ground, but gradually get smaller as they approach the tips of the stems. Here, the leaf tips are without teeth, but the lower leaves have a few. It produces large numbers of 1-inch flowers on panicles at the end of each stem. The white elliptical ray flowers surround a central yellow disk. Though one of its other common names, frost aster, suggests that it blooms in late fall, it finishes flowering in my landscape by early November. This aster tends to freely sucker, and extensive patches of it form over time in a landscape. It is easy to grow in a wide variety of conditions, but prefers to have good air movement and sunlight. Rice button aster (Symphyotrichum dumosum) Rice button aster is a variable species that might actually be a collection of closely related ones. I’ve seen it in a variety of flower colors and growth forms, but its foliage characteristics are constant as is
its tendency to sucker extensively. This is another ubiquitous species in Florida and has been reported even into the Florida Keys. It occurs in a wide variety of upland habitats and growing conditions though it also is reported to tolerate moist soils. After it reemerges in the spring, it produces a great number of thin wiry stems. The narrow linear leaves are sessile, without teeth and alternate along the stem. The lower leaves may be up to 4 inches long, but they quickly become reduced in size as they occur up the stem. Large numbers of 1-inch flowers occur atop the many branching panicles produced at the tips of the stems. The ray flowers vary in color from white to lavender and surround a yellow central disk. The blooming period varies, but mine always flower in mid-fall and are finished by November. Rice button aster is one of the few species that is widely available from native nursery sources in Florida. Its adaptability makes it a good choice for most landscapes, but because of its tendency to sucker extensively, it requires some management if used in a mixed species wildflower setting. Calico aster (Symphyotrichum lateriflorum) Calico aster occurs in most counties within the Florida Panhandle and the northern peninsula in moist but welldrained soils common to forest margins, stream borders, low wet woods, wet prairie depressions, and along roadsides. After reemerging in the spring, it reaches 2-3 feet in height on erect somewhat woody
stems. These stems are green and covered with soft white hairs but turn reddish by summer. The leaves alternate on the stem and are oval to elliptical, and dark green in color with sparingly toothed margins.
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hairs, though a reticulated network of secondary veins is visible on the underside of the leaves. The basal leaves are 1-1.5 inches long and the stem leaves are nearly that size as well. Flowering occurs in mid-fall in Florida. Flowers occur in a panicle atop the central stem and to a lesser extent at axils near the top. They are composed of white ray flowers with a yellow central disc. Each flower is about ½ inch across. Although extremely common elsewhere, lanceleaved aster is not currently propagated in Florida. I do not have experience growing this aster in my landscape at present.
They are shiny with hairs only along the mid-vein on the underside of each leaf. The lower leaves are about 1 inch wide and 6 inches long, but the leaves become decidedly smaller and more linear as they ascend the many branching stems. As its Latin name suggests, the upper stems and the flowering heads are often produced more to one side than the other. Calico aster typically flowers in September to October, earlier than most other native asters. A great many blooms are produced, composed of white to slightly rosy ray flowers with yellow disk flowers that turn purplish red a few days later. I currently have limited experience growing calico aster in my Pasco County landscape, but it is reported to do best in part-sun and moist soil. Given these conditions, it would seem a good choice along a woodland edge where a flowering ground cover is desired. Simmonds’ aster (Symphyotrichum simmondsii) Simmonds’ aster has been vouchered in nearly every county of Florida and is likely present in the others as well. It is an adaptable species, occurring in a wide variety of well-drained, moist sunny or mostly sunny habitats. The predominantly shiny stems are stout and reach a mature height of 3-4 feet. The basal leaves can be up to 6 inches long, are lanceolate and slightly toothed. As they alternate up the stems, they become more linear and are without teeth on the margins. Simmonds’ aster produces large numbers of flowers in late fall, blooming from late October into early January depending ●
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on latitude. Numerous white ray flowers surround the yellow central disk flowers. The ray flowers are sometimes a blushed lavender in color and the central disk flowers often turn reddish as they age. Each flower is about 1 inch in diameter. This aster species is very rarely offered for sale by native nurseries. The specimens I have were purchased and mislabeled as a different species. This is a wonderful aster for large landscapes where extensive colonies of this plant would be appreciated. Lance-leaved aster (Symphyotrichum lanceolatum) Lance-leaved aster is also known as white panicled aster. It occurs in nearly every state and Canadian province, but it is vouchered from only four counties in the Florida Panhandle. Throughout this vast geographic region, it is a highly variable species. Taxonomists divide it into two subspecies, each with several varieties. Ours is placed in subspecies lanceolatum which occurs throughout the eastern half of North America and in variety latifolium which stretches from Florida into Maine. It is found in a wide variety of habitats from moist to well-drained soils, in sunny open locations. It reaches a mature height of 2-3 feet and branches sparingly as it grows. The stout stems are light green to reddish in color and characterized by having vertical lines of white hairs. The leaves are sessile, narrow and elliptical, generally without teeth, and alternate along the stems. A few teeth may be found on the basal leaves. They also are shiny green and without
Willow-leaved aster (Symphyotrichum praealtum) Willow-leaved aster is another native aster found in just a few northern Panhandle counties, but is common outside Florida. It is most often encountered in moist soils in sunny open locations. This herbaceous perennial forms an erect woody stem after emerging in the spring and reaches a mature height of 3-5 feet by summer. The leaves are narrow and willow-like, alternate along the stem and are slightly toothed. Small veins form a CONTINUED ON PAGE 15
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Article and photos by Roger L. Hammer
Love Those Spider Lilies Florida is blessed with 14 native members of the genus Hymenocallis, and 9 of them are endemic to the state, being found nowhere else on Earth. Of those endemics, 4 of them are only known from single counties, while 4 others are restricted to 3 or 4 counties each, mostly in the Florida Panhandle. Hymenocallis is Greek for “beautiful membrane” and refers to the hymen-like membrane that spreads between the similar-looking sepals and petals (collectively called tepals). The genus belongs to the Amaryllis Family (Amaryllidaceae), and are not true lilies, despite the common name. The Royal Botanic Gardens, Kew recognizes 64 species worldwide. In Florida, the white, fragrant flowers are mostly pollinated by day-flying and night-flying sphinx moths that dust pollen onto their wings as they sip the sweet nectar from the floral tube, then the pollen is transferred to the next flower they visit. Spiderlily pollen is either yellow or orange, depending on the species. They are not easy to identify because the flowers are quite similar, but knowing which county you are in narrows your choices considerably, and the number of flowers produced is also helpful to direct you to the right species. For a botanical key, visit the online Flora of North America at http://www. efloras.org. Hymenocallis choctawensis, or Florida Panhandle spiderlily, is found from Escambia County west to Gadsden and Liberty counties in the Florida Panhandle with its range extending into eastern Louisiana and across southern Mississippi,
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Alabama, and Georgia. It is most abundant along stream and river banks, and was named for the Choctaw tribe of Indians who were originally based in Mississippi and Alabama. This species is considered to have great horticultural potential as a landscape plant within its natural range, with showy, highly fragrant flowers appearing from spring into summer. Flowers range in number from 2–8 but there may be as many as 12. The leaves are deciduous in winter and arise from a rhizomatous bulb. Hymenocallis crassifolia is called the Coastal Plain spiderlily or the Coastal Carolina spiderlily. In Florida it is known from Union, Nassau, and St. Johns counties in the northeastern corner of the state but it ranges north along the coasts of Georgia, South Carolina, and into the southeastern corner of North Carolina. Its habitat is stream and river banks, bogs, brackish marshes, and ditches. It is distinguished by its leaves that are held nearly erect along the entire length, which arise from rhizomatous bulbs. From 2–3 fragrant flowers appear in late spring and open one after the other. The species name, crassifolia, references its thick leaves. Hymenocallis duvalensis is known colloquially as the Dixie spiderlily or the white sands spiderlily. It is known from Nassau, Duval, and St. Johns counties discontinuously west to Levy, Lafayette, and Leon counties and extending into south-central Georgia. Distinguishing characteristics are the very narrow leaves that are low-spreading to nearly horizontal. Intensely fragrant flowers number 2–3 and appear in early
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to mid-spring. Look for large, spreading populations along stream and river banks as well as adjacent floodplains. Hymenocallis franklinensis, or Cow Creek spiderlily, is endemic to the lower Ochlockonee River system of Liberty, Franklin, and Wakulla counties in the Florida Panhandle. It is very similar to H. crassifolia except that the flowers of H. franklinensis are noticeably larger and the Flora of North America treatment states that “the scape bracts are broader at the base and taper in the distal half.” It inhabits floodplains of slightly brackish rivers and streams and produces 2–3 flowers in springtime. Hymenocallis gholsonii is endemic to Liberty County in the central Panhandle where it is commonly called Gholson’s spiderlily and was named to honor noted Florida botanist Angus Gholson (1921–2014). It was first discovered near the small town of Sumatra in the Apalachicola National Forest in 1991 and was described in 2009, making it the newest addition to the genus in Florida. In fact, it is so new that it does not appear in the Flora of North America. Wide leaves are held erect and paired flowers can be found through spring and summer. Hymenocallis godfreyi is known as Godfrey’s spiderlily or St. Marks Marsh spiderlily. It was described in 1994 to honor Florida State University botany professor Robert Godfrey (1911–2000) and is only known from Wakulla County where it was first discovered by Robert Godfrey in 1990 near the junction of the Wakulla and St. Marks Rivers. It produces 2 flowers with one opening slightly before the other, and can be found inhabiting brackish marshes near the aforementioned rivers. The yellowish green leaves are short, as is the flower stalk. Hymenocallis henryae var. glaucifolia has no common name but it is noted for its distinct blue-green (glaucous) leaves, clumping growth habit, and long sepals and petals. The name glaucous-leaved spiderlily would be fitting. It is endemic to Liberty County in the Florida Panhandle and occurs in cypress depressions along the edges of pine flatwoods. The Flora of North America notes that it is of conservation concern. Hymenocallis henryae var. henryae is known as Henry’s spiderlily or green spiderlily, with the latter name referring to the greenish sepals and petals. It was named to honor botanist Mary Gibson Henry (1884–1967), who once served as the director of the American Horticultural Society. The bulbs are not rhizomatous and the leaves are deciduous in winter. The paired flowers are faintly fragrant. It is a state-listed endangered species endemic to Walton, Bay, and Gulf counties, and is being considered for federal protection. Hymenocallis latifolia is perhaps the most well-known species in Florida, occurring along both coasts from Volusia and Hillsborough counties south into the Florida Keys, with one outlying coastal population in Franklin County in the Florida Panhandle. It is commonly called the beach spiderlily or dune spiderlily, due to its propensity to grow on beach dunes, but another common name is mangrove spiderlily for its frequent occurrence along the fringes of mangrove habitat. It is quite salt tolerant and is the largest species found in Florida. It is also the species that is most commonly cultivated in Florida,
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with wide leaves up to 3’ long, lax sepals and petals, and 9–15 showy flowers with orange pollen. Hymenocallis occidentalis is known from Liberty, Gadsden, Leon, and Jefferson counties in the Florida Panhandle but also ranges into Georgia, Alabama, Mississippi, and Louisiana north to North Carolina, Tennessee, and Kentucky, then west to Illinois, Missouri, and Indiana. The bulbs are not rhizomatous and bear 5–12 deciduous leaves, with 3–9 flowers that open sequentially. It is considered to have the widest distribution of any other species and is the most cold-hardy. Hymenocallis palmeri, or alligatorlily, is endemic to cypress swamps, wet prairies, pine flatwoods, and moist roadsides from Hillsborough, Polk, Osceola, and Brevard counties south through mainland Florida, with outlying populations in Bradford and Duval counties in northeast Florida. It was described in 1879 by botanist Sereno Watson (1826–1892) to honor botanist Edward Palmer (1829–1911). It produces a solitary flower with upturned sepals and petals, and narrow leaves. It is the common species in the watery glades of Everglades National Park, where it grows alongside its relative, Crinum americanum. Hymenocallis puntagordensis is endemic to Charlotte County near the city of Punta Gorda. It is called the smallcup spiderlily because of its small, central staminal cup (corona). It is critically imperiled yet it is unlisted by any agency. It bears 3–5 flowers with long, narrow sepals and petals. Hymenocallis rotata is endemic to Wakulla and Jefferson Counties east to Columbia and Duval counties, then discontinuously south to Orange and Hillsborough counties. It is called the spring-run spiderlily because it inhabits the banks of spring runs, which are the shallow streams that flow out of Florida’s springs. It sometimes forms large colonies along spring-runs and is a stunning sight when in flower. The leaves are deep green with 2–4 showy flowers that are usually open at the same time with outward-spreading sepals and petals. It was once thought to be the only spiderlily found in the Florida Panhandle. Hymenocallis tridentata is called the Florida spiderlily and is endemic to open, sunny, wet habitats from Hillsborough County south to Lee County, plus Indian River, Glades,
Hendry, and Miami-Dade counties. In Miami-Dade County I have only seen it in the wet prairies along the road leading to the Pa-Hay-Okee Overlook in Everglades National Park. It can be immediately separated from H. palmeri that shares its habitat in the Everglades by its paired flowers. So, if you’re looking for some adventure, put on shoes you don’t mind getting wet and go look for Florida’s spiderlilies. And good luck identifying them! Atlas of Florida Plants. 2024. https://florida.plantatlas.usf.edu Flora of North America. N.D. http://www.efloras.org. Hymenocallis. http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=116083 Hammer, Roger L. 2018. Complete Guide to Florida Wildflowers. Globe Pequot Publishers. Guilford, CT. Weakley, Alan S. 2021. Flora of the Southeastern United States. University of North Carolina, Chapel Hill, NC.
Roger L. Hammer is an award-winning professional naturalist, author, botanist and photographer. His most recent books are Paddling Everglades and Biscayne National Parks and Foraging Florida – Finding, Identifying, and Preparing Edible Wild Foods in Florida. Find him online at www.rogerlhammer.com.
Dune Savers CONTINUED FROM PAGE 2
The support and cooperation from the City of Treasure Island has been an effective communication corridor for promoting native plants to the city and its residents, along with the accomplishments of the volunteer Dune Savers. In fact, the Sunset Beach/Treasure Island group has inspired a recently established Dune Savers volunteer group in the City of St. Pete Beach that continues this important conservation effort on their local dunes. Dune Savers is a concept all beachfront communities could adopt and it would make a great initiative for FNPS chapters around the state. Barbara Driscoll and Marcia Warren are volunteers with The City of Treasure Island and are members of the Pinellas Chapter of the Florida Native Plant Society.
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Symphyotrichum Asters CONTINUED FROM PAGE 11 definite reticulated pattern on the underside of each 3-5-inch-long leaf. The underside of each leaf also is whitish in color, in contrast to the shiny green upper surface. Flower clusters form atop the main stem in early to mid-fall. The small flowers are about 1 inch across and are composed of many pale lavender ray flowers surrounding a yellow disk. This disk often turns reddish as it ages. Willow-leaved aster often forms extensive colonies in the wild but is said to seed profusely as well. This is another aster that I have not personally grown in my landscape and it is not currently available commercially from Florida native nurseries. Smooth white oldfield aster (Symphyotrichum racemosum) Smooth white oldfield aster has a common name that describes a lot of its general ecology. It occurs naturally in Florida in the Panhandle and in Alachua County but
is widespread throughout much of eastern North America. This species is sometimes confused with others. For the most part, it occurs in sunny wetland habitats, though it is adaptable to somewhat drier locations. At maturity, its stout woody stems reach a height of 2-3 feet. The shiny green sessile leaves are linear and 2-3 inches long near the base of the plant, decreasing in size as they near the top. They have entire margins and alternate along the stem. Flowering occurs in early to mid-fall in an open panicle atop the main stem. Numerous white ray flowers, occasionally tinged in pink, surround a yellow central disk. It is a species best used in seasonally wet to moist habitats and this characteristic would be the first step in distinguishing it in the field from its close Florida relatives. It tends to have far fewer involucral bracts than S. dumosum, much shorter bracts than S. lanceolatum and ascending involucral bracts instead of the spreading ones of S. lateriflorum.
Atlas of Florida Plants. 2024. https://florida.plantatlas.usf.edu Wunderlin, Ricard P., Bruce F. Hansen, and Alan Franck R. Flora of Florida. Volume VII: Dicotyledons, Orobanchaceae through Asteraceae. Gainesville: University Press of Florida, 2020.
Craig Huegel has a PhD in Animal Ecology from Iowa State University. He is Collections Curator at the University of South Florida Botanical Gardens, and is the author of several books on native plants and landscaping for wildlife. His latest book is The Nature of Plants: An Introduction to How Plants Work, published by the University Press of Florida.
Calling All Native Landscape Enthusiasts!
Do you have a stunning native garden, a thriving habitat restoration project, or a commercial space buzzing with pollinators? The Florida Native Plant Society (FNPS) wants to recognize your hard work and dedication!
SHOWCASE YOUR WORK:
Submit your project and have the chance to win recognition, media exposure, and FNPS membership! Award Categories: • Residential Landscaping • Commercial & Institutional Landscaping • Habitat Restoration & Conservation • Pollinator & Wildlife Demonstration Gardens Awards & Recognition: • Native Garden of Excellence (Top Honor) • Native Garden of Honor Benefits for Winners: • Award recognition plaque • Feature story in FNPS magazine, website & social media • Local & statewide media exposure • FNPS membership (for Garden of Excellence winner) Submission Deadline: August 9th, 2024 Visit https://www.fnps.org/what-we-do/landscaping/landscape-awardsinformation for complete details, rules, and application forms.
Let's celebrate Florida's native beauty together!
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