western sycamore

WESTERN SYCAMORE: Platanus racemosa, aliso (Spanish), sā-vār or shă-var’ (Tongva)

ORIGIN: California Floristic Province, riparian areas near the coast and some inland areas

MATURE HEIGHT AND WIDTH: 40-80 ft. tall, 30-50 ft. wide.

GARDENING NOTES: winter deciduous; thrives with significant amounts of water in well-draining soils; best planted near swales, streams, or seeps; otherwise supplemental moisture is required; drops large leaves on anything planted underneath.

If You Are At The Garden

IN EARLY SUMMER, before the dry heat hits and the broiling sidewalks become truly empty, you will see the intricate shuttlecock-shaped blooms of this species. Look for extravagant umbels of pink-and-white flowers at the terminus of tall slender stems.

Civilization

You may also see, if the timing is right, a lot of colorful living things clinging, crawling, eating, mating, killing, and fluttering about on these plants. Inspect the stems, particularly right below the umbels of white-pink flowers: you might find clusters of bright yellow aphids with thin black legs. These are oleander aphids, Aphis nerii, herbivores originally from the Mediterranean and, since gone global or “cosmopolitan” — now flamboyant citizens of the world.

NARROWLEAF MILKWEED: Asclepias fascicularis, to-hah’-ce-aŕ (Tongva)

ORIGIN: California Floristic Province, throughout California except high mountain ranges

MATURE HEIGHT AND WIDTH: 1.7 ft. to over 3 ft., individual plants 1 ft wide, forming colonies

GARDENING NOTES: winter deciduous; blooms in the summer at Arlington; do not use any pesticides because it is a food source for many insects including monarch butterfly caterpillars; all parts of this plant are toxic when consumed, but A. fascicularis poses special risks to horses.

Oleander aphids reproduce in the wild almost entirely through parthenogenesis, which is reproduction via unfertilized eggs. The process of parthenogenesis doesn’t require males. Hence, in the wild, there are at most very few males: in fact, only a few naturally occurring males of the species had ever been observed as of 1993, although they have been shown to exist in potentia in the laboratory.

Along with aphids, you may observe a number of other gaudy citizens of the early 21st Century milkweed civilization. The small milkweed bug, for instance, is a black and reddish-orange true bug that eats milkweed seeds. The western milkweed longhorn is a similar-looking beetle whose red carapace is decorated with black dots. You can distinguish the latter from small milkweed bugs by the patterns on its back: milkweed bugs have aggressive crossed bars, and milkweed longhorns have stylish spots! True bugs such as small milkweed bugs also always have a sharp beak, which they use to pierce plants or prey and suck out their insides.

If you are very lucky, you will also spot a caterpillar of the monarch butterfly. Much has been written about this species, so this guide won’t expand on the subject. Suffice it to say that striped monarch caterpillars, like the insects mentioned above, are brightly colored as a form of deterrence. Their costumes signal to predators that they are this kind of insect, a kind of insect (hopefully the predator remembers) that is very, very unpleasant to eat. And they are unpleasant, because their bodies are laced with toxic compounds from their food, Asclepias fascicularis.

These brightly colored warnings also apply to humans for different reasons: please do not touch!

HUMMINGBIRD SAGE is a shade-loving groundcover with whorls of flowers so colorful that the illustrator of this guide has remarked they look like showy garden cultivars — escapees from secret underground labs at the Royal Horticultural Society. They are, however, native to California’s oak woodlands and chaparral. If you are at the garden in the winter and spring, the flowers and leaves will be visible. Otherwise, you may need to hunt a bit to discover the sprawling stalks. If in doubt about identity, squeeze a quilted leaf and check for a “fruity” cheerful odor.

WHAT’S A WHORL?

The flowers of hummingbird sage form a whorl (a ring) around the peduncle (the main stem) of the plant’s flower spike. The reddish-to-purple

HUMMINGBIRD SAGE: Salvia spathacea, diosita (Spanish), qimsh or pakh (Chumash)

ORIGIN: California Floristic Province, southern California up to Solano County near Sacramento

MATURE HEIGHT AND WIDTH: slowly spreading rhizomatous groundcover 1-3 ft. tall scale structures the flowers grow out of are not petals, but modified leaves called “bracts.”

GARDENING NOTES: grows well in dry shade under oaks; unusual purple-red flowers attract hummingbirds; appropriate for pot culture; a perfect landscaping plant in Pasadena.

These flowers evolved in tandem with bird pollination, which has the occult-sounding name “ornithophilous” or bird-loving. Nectar is stored deep inside the tubular flower while the flower’s pollen-bearing stamens extend past its lip (see them poking out in the illustration). In fact, the nectar and stamens are separated just enough that foraging hummingbirds, sipping nectar, dunk their heads in pollen. Some biologists hypothesize that these are fine-tuned adaptations specific to bird pollinators, since pollen is less likely to fall off birds’ feathers than their smooth beaks, and thus more likely to make it to the next flower.

The World Arboreal

Look around you. Hummingbird sages grow in dry, open understories of coastal oak and mixed woodlands. These dappled worlds are surprisingly dense with plant, animal, and fungi species. Take just the animals: oaks provide shelter, food, or are indirectly “associated” (e.g. as hosts for prey species) with thousands of animal species including woodrats and mule deer, owls, skinks, arboreal salamanders — they climb trees — and many crawling and gnawing nameless things.

Oaks are also the main engine of so-called “nutrient cycling” in their kingdoms. They add carbon and other nutrients to the forest floor via leaf litter. And they use their extensive roots to capture the nutrients again (aka “cycling”) before they wash away.

THIS FLOWERING SHRUB SUPPORTS A COLOSSAL number of animals as shelter, farm, and pantry. It blooms for a long period in the late spring and summer with dry umbels darkening to rust-coloured poms, adding texture to hillsides. California buckwheat is a caterpillar host plant for Plebejus butterflies like the modern-looking Acmon blue plebejus, which wears the subtle colors of an expensive scarf, as well as many others.

Keystones And Arches

California buckwheat is a keystone species. It holds up the arches of some quintessential California plant communities including coastal sage scrub. Keystone species are important enough to an ecosystem that their removal would be highly disruptive to species diversity and abundance. Remove a keystone and the arch comes crashing down — that’s the metaphor.

California buckwheat is a plant, but the keystone concept was first introduced to describe animal predators by Robert Paine, a biologist who studied the small and hardy things living in tidepools. Although he worked with small creatures, Paine was a large man, reportedly 6’6”, and, in photos, he glows with a ruddy countenance and happy demeanor, with extra-large waders pulled up to his chest.

In “Food Web Complexity and Species Diversity,” he describes an experiment establishing that the predatory starfish Pisaster ochraceus is a keystone species. Pisaster is a purple and orange starfish from the

Washington coast that eats barnacles, mussels, chitons, and other molluscs in the tidal zone. In the experiment, Paine compared two sets of tidepools, one in which he had removed the starfish — by literally tearing them from the rocks and throwing them out to sea — and another which he left undisturbed. The species composition of the undisturbed tidepools remained unchanged during the experiment. But the tidepools without starfish were quickly altered and for the worse : within a year, a species of mussel had almost completely dominated the area, pushing out other molluscs and decreasing the total number of species in the local food web from 15 to 8 — a decrease in local species richness of nearly half!

This experiment showed Paine that, although the starfish doesn’t care a whit about it, Pisaster ochraceus is a biodiversity promoter and hence a keystone species: it keeps mussels and barnacles, both of which are effective at dominating the real estate of this liminal habitat, at levels low enough for other species to compete.

CALIFORNIA BUCKWHEAT: Eriogonum fasciculatum, valeriana (Spanish), jm’ilh (Kumeyaay), tswana’atl ‘ishup (Chumash), wilakal (Tongva)

ORIGIN: California Floristic Province and other parts of the Southwestern United States and Northern Baja into the Great Basin, found in chaparral and coastal sage scrub

MATURE HEIGHT AND WIDTH: 2-6 ft. high, 2-3 ft. wide

GARDENING NOTES: makes a long-lasting cut flower; provides year-round interest in mediterranean gardens due to its summer blooms and beautiful seed clusters; ideal for habitat gardens in Southern California where it is ubiquitous on nearby mountain slopes and hillsides.

DROOPING, INFLATED SEED

PODS dangling from the tips of criss-crossed stems help identify this striking shrub. In addition to the pods, you can recognize it by its yellow firework flowers and pungent odor. Bladderpod supplies food to a great many pollinators including hummingbirds, and it can produce blooms in summer when other California natives enter dormancy.

A Divisive Scent

Bladderpod, with the sobriquet “stinkweed,’’ produces a distinctive odor when its leaves are damaged. The Los Angeles native plant organization, Theodore Payne Foundation, describes it as “smelling like bell peppers,” but others say it smells similar to burnt tires. (Bell peppers are, in any case, divisive.) One present

BLADDERPOD: Peritoma arborea (Cleomella arborea), ejotillo (Spanish), peshaash (Kumeyaay)

ORIGIN: southern California Floristic Province down into Baja California

MATURE HEIGHT AND WIDTH: 1.5-6 ft. high, up to 6 ft. wide, although seldom this large in gardens staff member at Arlington finds the odor repugnant, but the author of this guide would describe it merely as “savory.” The source of the smell are compounds (glucosinolates) that the plant likely produces to defend against insect pests and other enemies such as fungi. These compounds are also produced by members of the mustard family, such as collard and brussel sprouts, to which bladderpod is related. Pinch a leaf to smell it for yourself!

GARDENING NOTES: flowers for a long period, reblooming throughout the year with extra water; bright yellow flowers; regarded by some as one of the easiest Southern California natives to grow; an excellent choice for habitat gardens.

Edible Flowers

The flowers of bladderpods are eaten by the Kumeyaay, who are the Indigenous people of southernmost California and northern Baja California. The anthropologist Michael Wilken-Robertson reports that the Kumeyaay eat the flowers and buds by “nipping them off with thumb and forefinger” before a long boiling process during which the bitter water is replaced several times. The cooked flowers are rolled into a ball and can be eaten plain or with a tortilla.

Shaped By The Summer

Bladderpod is an endurer. Granted, this doesn’t distinguish it from other perennials that also live through less-than-ideal conditions. What sets it apart from lavender (a doughty barbarian compared to a cultivated rose) or vain hibiscus are the conditions that it’s adapted to endure: extreme environments in which water is absent and heat and sunlight present a constant threat. As an adaptation, it has developed a waxy, pale leaf and stem, which reduce evaporation and cont. p.38 »