A Visit to Huntington Gardens
We had the opportunity to visit the Huntington Gardens in mid-November with friends and, unfortunately, only had time to visit the desert collections, one of many gardens maintained by this iconic institution. The gardens, for readers who are not familiar with them, are part of The Huntington Library, Art Collections, and Botanical Gardens in San Marino, California (which lies just south of Pasadena). To mention only a few of the highlights of the institution, one needs only to note that the art collection includes Gainsborough’s Blue Boy and Lawrence’s Pinkie, while the library holds such masterpieces as a velum copy of the Gutenberg Bible (one of 32 complete volumes), an early edition of Chaucer’s Canterbury Tales, and an original edition of Audubon’s The Birds of America.
Of the several gardens maintained on the grounds, the desert collection is considered one of the most complete in the world, with some 5,000 species, many of which are rare, representing all of the arid regions on the Earth. Our hosts suggested the desert garden, but that the time available—only a few hours—was not nearly enough to enjoy the richness of the collection. We did our best. The illustrations selected for inclusion here are those of species (or at least genera) that I recognized, or whose name tags were available. Some background reading revealed, not surprisingly, that not all authorities agree on proper names for some of plants that we saw. I will use the names that appear on the garden’s tags, although I will include some comments from time to time.
We can start with the most common family of desert plants, the cactus family. Cactaceae are represented below by four genera, Borzicactus, Echinocactus, Opuntia, and Oreocereus. Borzicactus comprises a group of columnar cacti native to Bolivia, Ecuador, and Peru. The plant shown here is B. sericatus. Some authorities prefer the name Cleistocactus (Mabberley, 193). Echinocactus grusonii, a native of Mexico, is known by several common names, the most familiar being the Golden Barrel or Golden Ball cactus, although I have seen it described as Mother-in-Law’s Cactus in several sources. Our next genus, Opuntia, is likely to be better known than the South American genus, although its occurrence in the Americas ranges from British Columbia to the Straits of Magellan. The species shown here is O. basilaris, the beavertail cactus, which occurs in the arid southwestern parts of North America. Oreocereus fossulatus is a native of western South America. Mabberley (p. 115) lists this genus as synonymous with Borzicactus. Many of the members of this genus (under whichever name) are characterized by long white hairs.
One of the more interesting sets of desert dwellers in southwestern North America belong to the genus Fouquieria, the sole genus in the Fouquieriaceae. There are 11 species in the genus represented here by juvenile and mature specimens of F. columnaris a native of Baja California and Sonora, Mexico. (At one time this genus was referred to as Idria, a name no longer accepted.) Readers familiar with the deserts of Arizona would recognize F. splendens, the ocotillo, as belonging to this group. This tall, whip-like plant responds to infrequent rain in the desert by producing a fresh crop of red blooms at its tips. The photograph was taken in the Anza-Borrego Desert in southern California.
Fouquieria columnaris, described by one author as an upside-down carrot with spines, is perhaps best known in the informal scientific literature as the boojum. The boojum, as readers of classic nonsense literature will recall, was a particularly dangerous variety of Snark, which was the target of the quest in Lewis Carroll’s The Hunting of the Snark. When asked about the boojum, Carroll replied that it was indescribable, and that it should stay that way.
The tall, thin green plant with the gray tips on the left of Huntington View is the Madagascar ocotillo, a species of Alluaudia that bears no relationship to the ocotillo we just visited, other than its capacity to live in a desert habitat. Alluaudia (one of the genera that comprise the Didiereaceae) consists of six species native to Madagascar. The family—seven genera and 22 species in all—has a natural distribution that includes Madagascar and southern and eastern Africa.
Flanking Alluaudia in the photograph are two individuals belonging to the large genus Aloe. Specifically, the plants are representatives of A. dichotoma, one of 446 species (Mabberley, p. 31) of the wide-spread genus. Pictured here as well are a single individual in the Huntington collection, with a friend for scale, and a small population of the plants in their native habitat in Namibia. The common name of this plant is quiver tree, or Kokerboom in Afrikaans, which identifies the local use of a hollowed length of stem as a quiver for arrows.
Our next two examples come from Crassulaceae, a family known to most gardeners and especially to collectors of easy-to-grow succulents: Kalanchoë is likely to be among the most familiar members of the family. Also prized by collectors are members of the genus Aeonium, here represented by A. arboreum, one of the largest members of the genus, and a prominent member of the flora of Gran Canaria. Most of the 35 species of Aeonium occur in the Macaronesian Islands (Canary Islands, Azores, Madeira, Cape Verde Islands) with outliers in Tanzania and in Arabia. Aeonium arboreum var. atropurpureum (the purple-leafed plant growing at the foot of the central Aloe in Huntington View). This variety is variously known as variety ‘Zwartkop’ or ‘Schwartzkopf’ which, of course, translate as black head.
The other example from Crassulaceae is Tylecodon paniculatus, one of the 46 species of this fascinating genus that occur in the South African floral kingdom. Several species of Tylecodon are prized by collectors.
One of the oddest members of the Huntington collection is the so-called bottle or pony-tail palm, or elephant-foot tree. Beaucarnea recurvata, a native of Mexico, is recognized as belonging to the genus Nolina by most authorities (Mabberley, p. 586). It is placed in the family Asparagaceae (some authorities preferred Dracaenaceae).
Two representatives of the Apocynaceae were photographed on our tour, one a species of the genus Pachypodium, and the other a species of Stapelia. Pachypodium lamerei var. lamerei is a native of Madagascar. This species produces flowers that closely resemble those of plumeria in color and aroma. I am very familiar with plumeria but have not had the pleasure of seeing (or smelling) Pachypodium in bloom. Most of the 25 species of this genus occur in Madagascar with a few in southern and western South Africa.
The second member of this family here is Stapelia grandiflora one of 47 species in the genus that are spread between tropical and southern Africa. Stapelia grandiflora, as its names implies, features large flowers that can be darkly pigmented and produce an aroma of decaying flesh which is attractive to carrion flies who then lay their eggs in the flower.
This phenomenon is not unique to Stapelia, or, indeed to members of Apocynaceae. The capacity to emit aroma chemicals that mimic carrion, or fecal matter, has been reported from several other families, as well; the list includes Annonaceae (e.g., species of Annona), Araceae (e.g., Amorphophalus titanum, skunk cabbage), Orchidaceae (Cypripedium species), and Rafflesiaceae (e.g., Rafflesia). This is one of the many examples in the plant kingdom of convergent evolution where unrelated groups of plants have evolved to possess identical or very similar adaptations. For the more adventuresome reader I can suggest papers on chemical mimicry and insect visitation by A. Jürgens and coworkers, with additional references to their work including a detailed study of the chemistry of Stapelia relatives.
One of the most useful plants growing in the desert garden is Jatropha curcas. This member of Euphorbiaceae, the spurge family, is a native of tropical America but is widely cultivated. Parts of the plant are thought to have medical properties, the oil can be used in soap making and can be burned for illumination. Perhaps the most potentially important application involves using the oil as a source of motor fuel. A drop of oil can be seen where I scratched one of the fruits.