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Some Californian Flowering Shrubs by Lester Rowntree

The wayfarer in the sequestered regions of California develops a strong affection for many of the less colorful shrubs of the chaparral, desert, mountains and shrubs. It is, however, the more brilliant flowering shrubs which arrest the attention of the newcomers, who are generally inspired to possess and grow them. Among these latter shrubs and the “big four,” Romneya coulteri, Dendromecon rigida, Fremontia californica and Carpenteria californica, all quite worthy of the admiration which they evoke.

Of the four, Romneya coulteri, the Matilija Poppy, is the most impressive. Not only is it a gorgeous thing in the mass, as it ramps about in the cañons and the small empty stream beds known as “dry washes,” but it well repays closer inspection. In the bud the smooth gray-green sepals release crumpled swan-white petals which slowly unfold a fragrant seven-inch flower. Young blooms keep their crepe-like quality but age erases the lovely wrinkles and before they fall the silky petals are paper-smooth. In the center of the flower the heavily massed stamens poise in a symmetrical golden ball.

One of the charms of the Matilija Poppy is the nice harmony between the flower and the foliage - large smooth divided blue-green leaves and gray-green stems. The plant is comely all the year except in the late autumn, when for its benefit as well as that of the grower, the stems should be cut to between six and twelve inches off the ground. The enforced cessation of activity conserves the plant’s energies and strengthens its root growth - sometimes an unnecessary measure, since Romneya coulteri is a rampant grower and if given the chance will claim a whole hillside, thriving in any loose, well-drained soil (but with an antipathy for heavy clay). Sun and aerated ground are its chief needs. Moisture and drought it treats with indifference, associating cheerfully with the flame-tongued Fouquieria splendens in the blistering heat and parched sand of the vast inhospitable desert, and equally at home in the shelter of gentle English gardens, where you find it thoroughly domesticated, trained fan-shape up the side of a house, or, refined and poised, making a background for plump blue hydrangeas.

As the seed, fresh or stale, seems to be equally loath to germinate, even when fired, root cuttings, from November to March, make the quickest method of reproduction.

Romneya coulteri is hardy south of Washington, and as it will stand 10 degrees of frost can often be coaxed through a winter in the colder states.

Its botanical variety trichocalyx differs little from the type, seeming not much more than a different form with localized stands here and there in the southern part of the state. It has wider, grayer leaves, rounder and more hairy buds, blooms earlier, is lower growing and more floriferous and is possessed by a more vigorous determination to spread.

The uninitiated sometimes confuse that gigantic prickly annual, Argemone platyceras, with the Matilija Poppy. But the flowers of Prickly Poppy are smaller and the manner of growth entirely different.

Dendromecon rigida is a near relative of romneya and is a boon companion of the heat and sun-loving species of arctostaphylos and ceanothus. In its natural state it blooms the year round but is a little untidy in the management of its seed pods. While young, these narrow curved fingers are not objectionable, but after the explosion which releases and discharges the seeds, the two shredded valves hang on, quite useless, for an unnecessary length of time. The flower is a lovely thing, butter-cup yellow with a silken sheen, the pale green leaves are willow-shaped and stiff.

This Tree Poppy, like romneya, has so far withheld from us the secret of speedy seed germination. We do know that loose soil has something to do with it. For while in old remote stands not one seedling may be showing, in the empty dumped soil of new road banks thousands of young will appear, with one accord making this newly disturbed earth a glorious tree poppy garden. These seedlings make haste to bloom and when their small stems are covered with golden buds suggest plants of the English globe flower (Trollius).

The large satiny deep golden hibiscus-like flowers of Fremontia californica cluster round the many long flexible branches of this splendid shrub (or small tree). The rough leathery one-inch leaves are rich dark green above and downy underneath, not abundant but increasing when the plants are brought into cultivation. In California gardens, where its use is beginning, the first bloom often appears in January, but unless the rains are early and frequent the wild shrubs which occur singly or in large thicket-like stands on warm hillsides do not flower until May but will go on until July. It will stand about the same amount of frost as the Tree Poppy - not quite so much as romneya. And if it is used as a garden plant be sure not to overwater. At first the unusual amount of moisture incites the shrub to rank growth and for a year or so it speeds ahead. But before long the excess water will cut short its life and you will walk out one day to find your prized Fremontia a brown and dry derelict.

The variety mexicana is used in culture more than the type; the flowers are larger, more deeply colored and beautifully flushed with red-brown underneath; the leaves are more deeply cut, almost like small fig leaves.

Carpenteria californica fills the Californian heart with pride, for it is one of our choicest and rarest endemics. To not all of us is granted the sight of the native stands of Carpenteria californica. Happily the shrub is now dependably “in the trade.” If you know Cistus laurifolius and have seen a good sized bush laden with large white flowers, you have a good idea of what Carpenteria californica looks like, but the shrub is narrower, the white-faced leaves narrower and somewhat revolute, the large white flowers (borne also in clusters) are centered with a mass of golden stamens. The bark is silvery gray, and shreddy on aged plants, the shrub long-lived and about as hardy as the other three we have described, which means not hardy in the coldest gardens but possible where the thermometer does not drop below ten degrees.

Carpenteria and fremontia come readily from seed and carpenteria in particular is a quick grower. It is native on the open banks of cañons where the soil is of humus and shale, and like the rest is intolerant of poor drainage.

A close runner-up for this important four is Styrax officinalis var. californica, one species of a familiar genus of shrubs, many of which are in cultivation. It carries with it the curse of deciduousness, which for those gardeners with the evergreen complex puts our styrax beyond the pale. It is a spring flower with a not very long period of bloom. When crowded up among other shrubs of the chaparral its beauty is lost, but when as often occurs, one shrub escapes from the herd and gains foothold on some abrupt bank, its full beauty of form, leaf and flower is manifest. Styrax occidentalis var. californica is not far behind the other styrax species in grace.

The white fragrant bell-shaped pendulous flowers, about an inch long, drop from calyces of old gold and expand to show the inner wealth of golden anthers. Later they are followed by little tan nuts. If gently cracked the nuts will germinate quickly but the seedling must be transplanted young, for it resents interference more and more as it grows.

Aesculus californica, the California buckeye, reminds you of the lovely horsechestnuts which make a background for eastern lawns, but ours is wider and looser growing. It is rather more of a tree than a shrub, a very decorative, rather sprawling tree, deciduous, and showing as definite seasonal variations as does any flowering plant in this climate. The buckeye is a help to those of us who can never become accustomed to the lack of these natural demarcations. Almost subconsciously we note “The leaves are off the buckeye, so it must be winter,” “The buckeye is blooming—spring is well under way.” And when we see the big glossy mahogany-colored chestnuts thick among the dried palmate leaves under the tree, we know autumn is here.

The heavily scented chestnut-like flowers of Aesculus californica are light-colored when they first open in a pointed panicle - later the flowers turn pink and yellow and the panicle broadens.

From the Sierras comes the Bush Chinquapin, Castanopsis sempervirens. Its very name brings to mind the huge granite boulders among which it wanders, crouching close to withstand the wind, mingling with Quercus vaccinifolia or forming little colonies at the edge of forest of Tamrac Pine and Red Fir. The dark green azalea-like (though stiff) leaves are neatly veined and a beautiful golden green beneath. The terminal flower clusters have a sickly-sweet scent and are composed of upright catkins an inch long. The nut is shut into a prickly bur, closed in tightly at first, but at maturity lying cupped like an egg in a nest until seized by a squirrel or blown out by the wind. Often a bush will be blooming and fruiting at the same time. When brought into the garden it sulks, grows slowly, longs for the mountain tops and seems so utterly out of place that you suffer pangs of remorse at having taken it from those high slopes where snow covers it in winter and where the fierce light and strong wind of the summers are its springs of life.

The atriplex is one of those genera which seem to divide themselves equally between sea and desert. This habit is so frequent among the native flora of California that you are always trying to answer the questions: What common essential do these desert-ocean plants find? Why does one continually discover the same genera, often the same species, on hot, dry desert exposures and along the coast? Is it the sand? Is it the glare of light? How did they get into two such contradictory places and why aren’t they growing in the space between? Even in cultivation, coast species often thrive in the desert and contrarywise.

Atriplex canescens is one of a vast genus having this marked preference for either the coastal stretches or for that sun-baked area east of the southern Coast Ranges. The desert happens to be its choice. It is a wide, brittle, rather round shrub of about four feet, covered with small narrow gray leaves and smelling like a painter’s shop. The bark is a yellow tan and the young shoots red spotted with gray. It associates with creosote bush and the glorious parosela species. In late summer it takes on an unexpected splendor when it becomes heavily freighted with gold bracts in long dense panicles, leaning out and downward and smothering the bush in a cloud of glory.

Isomeris arborea is another inhabitant of the seashore and the arid wastes of southern California - a low shrub with the gray foliage characteristic of so many plants of the coast and desert. The yellow flowers in terminal racemes are showy with conspicuous protruding stamens. These are followed by large inflated and quite decorative seed-pods, which give the plant its common name of Bladderpod. The whole plant has a strong odor something like that of a vegetable soup composed largely of turnips. While I am properly impressed with its decorative qualities, Bladderpod is one of the few native plants for which I can feel little affection. Not because of its strong smell, which after all is its own affair and not worse than that of many another plant but because to my critical eye it seems a bit coarse and a little vulgar, both in flower and seed. However, it has acquired favor in gardens and has the good fortune that I seem to be alone in my prejudice.

Tree Tobacco, Nicotiana glauca, is not really a Californian at all, but a native of the Argentine, which long ago invaded the state and which has spread so rapidly that it is often thought an indigenous shrub. And ubiquitous as it is, it is so picturesque that it adds definite charm to the landscape - a tall slender shrub, loosely branched, with big smooth gray-green leaves and graceful terminal sprays of long tubular yellow flowers. The seed is borne profusely and is so fine that the wind scatters it easily. The dry stream beds and waste lands of southern California fairly bristle with little Tree Tobaccos. It would be used with good effect in landscaping work if it were not such a familiar object.

Beautiful as many of these conspicuous flowering shrubs may be, they have no firmer grasp on the affections of the wanderer in California’s uninhabited places than have certain members of the chaparral on desert, seacoast and mountainside. Those two imposing genera, arctostaphylos and ceanothus, have many lovable species; there is the spiraea-like Adenostoma fasciculatum, vibrant with the sweet chatter of wren-tits; the other Adenostoma species - sparsifolium - a stunning thing when seen against its natural background of boulder-strewn hillsides. There is the dainty Purshia, with little white wild rose flowers and leaves like tiny cloven hoofs; and all the flowering currants, some of which give us Christmas bloom; the blessed genus rhus, the rhamnus—and many other pleasant items of California’s liberal largesse, the flowering shrubs.

This article was originally published in the April 1935 issue of the National Horticultural Magazine. It was republished in the October 1955 issue.