Of Stomachs and Tongues—Gasteria 2
Gasterias, small to medium-sized South African members of the Asphodelaceae or Aloaceae, depending on which taxonomist is talking (each considered—though not necessarily by the same people—distinct families carved out of a too inclusive Liliaceae), may strike many people as a fairly unassuming genus of succulent plants, good for dish gardens and window-sills, but not really all that exciting. And, to at least a certain degree, there would be some truth in such a judgment. Since the late seventeenth century, when gasterias were first discovered by Europeans, they have served as reliable horticultural subjects, without the strict requirements in regard to light or watering times shared by many more spectacular or bizarre South African succulents. Gasterias are, nonetheless, interesting plants, with new discoveries in the genus being made even today, and with a number of extremely interesting species and forms quite different from the norm of the genus.
Gasteria received their name from a fancied resemblance of the flowers to a stomach, and unlike the symmetrical tubular flowers of their close relatives Aloe and Haworthia, Gasteria flowers generally curve or bend in the middle, resulting in a shape something like a kidney bean, or, in fact, a human stomach. Most Gasteria flowers are orange-red with a green tip, arranged along racemes that may be branched or simple. The plants hybridize freely, and, as is also the case with Haworthia, the first hurdle in making sense out of the genus was the need to determine which plants actually were naturally occurring species. Currently something less than twenty valid species are accepted, ranging from the tiny G. liliputana (even this now considered G. bicolor var. liliputana), with leaves barely an inch long, to the surprisingly large G. excelsa, which may grow into a rosette two feet tall and almost three feet in diameter. With only a few exceptions, however, all the species pretty much “look like” gasterias. In nature, gasterias avoid the harshest desert conditions of extreme aridity and total exposure to the sun. Instead, you’ll find them in habitats such as the succulent karoo, regions of scrub brush, often partly composed of bushy Mesembryanthemum and Euphorbia, offering scattered shade for less sun-hardy plants. Gasterias also frequently grow on steep slopes and rocky ledges, in the company of other succulents such as Crassula and, in some places, mesembs such as Conophytum and Gibbaeum. Because they grow in less uninhabitable areas than some succulents, the habitats of various gasterias are subject to human development, and many of the plants (which once were generally quite common) are finding their future in the wild increasingly precarious. A standardized Gasteria would have proportionately long, narrow, often pointed leaves, arranged distichously (two-ranked, like a spread out fan), and possibly decorated with white spots, raised white tubercles, and a pale, horny rim around the leaf margin. Most Gasteria offset, sometimes (as with G. liliputana), very profusely, sometimes slowly, and a few of the larger growing species don’t offset at all. In most species the distichous habit gradually disappears as the plant matures, and many gasterias end up as loosely arranged rosettes. In some forms the leaves reach upward, while in others they remain low to the ground; some species have thin leaves while in others they are very thick.Some of the more interesting species include Gasteria batesiana, with thick, rough-textured, channeled leaves, that forms a fairly tight rosette, G. disticha, that never grows into a rosette, and which may be densely covered with pearly tubercles, the also distichous G. pillansii, its dwarf variety, ernesti-ruschii, and its form (sometimes considered a distinct species), nelii. This last group of dwarfed plants grows in arid regions of Namaqualand (in northwest South Africa), and given good light will turn chocolate brown. Some species are less frequently seen in cultivation because they can become fairly large when mature, and some of these, including forms of G. carinata, G. bicolor and G. brachyphylla, can be very attractive with colorful leaves that show striking patterns of banding and spotting, or that may be covered with pearly white tubercles. The fairly recently discovered Gasteria rawlinsonii hangs down from steep cliff faces, and though it will grow upright in cultivation, its long chains of leaves distinguish it from all other gasterias. Another recently described species, G. pendulifolia, shares this pendent growth habit, but without G. rawlinsonii’s elongated stem. In some ways the most distinctive Gasteria in terms of overall appearance, G. armstrongii, not long ago was demoted from separate species to a variety of G. nitida. Disregarding their loss of status, good clones of G. nitida var. armstrongii retain their distinct appearance, with two-ranked, extremely thick leaves that look like tongues cast in dark green glass. Almost all gasterias are easy to grow. Most will thrive in any reasonably fast draining soil mix, and can take either partial shade or bright sunlight. Water once a week, with a winter rest period of water perhaps every three weeks suits them fine. Most will take a little frost with no problem if kept dry, but wet and cold conditions in winter can foster disfiguring black fungus spots on the leaves that, once present, will remain on the leaves permanently. Other than that, the plants generally remain disease and pest free. Many gasterias thrive outdoors in a slightly shaded spot in a succulent or rock garden. G. nitida var. armstrongii may want slightly longer intervals between water in winter, and the more arid growing forms of G. pillansii (such as nelii), though tolerating standard treatment, will do best if treated as winter growers, with a moderate rest period in summer. There also are a number of gasteria clones selected for their variegation, intense leaf color or unusual shape; these may be slower growing and hard to find, but not particularly difficult to grow. In addition, an increasing number of hybrid gasterias, purposefully bred rather than the product of random garden crossings, have become popular over the last several years because of their unusual leaf colors and textures.
The Garden has a fine collection of Gasteria, with labels reflecting various nomenclatural trends, and we always have plants available for purchase, including some rather unusual species, and more recently, some very attractive hybrids.
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