Some Plant Introductions from the Huntington Botanical Gardens

By: Kathy Musial

Kathy Musial is curator of living collections at the Huntington Botanical Gardens where she has worked for more than twenty-five…

More From This Author
Dombeya cacuminum. Photographs by John Trager, except as noted

Dombeya cacuminum. Photographs by John Trager, except as noted

Railroad tycoon Henry Edwards Huntington made his first trip to Southern California in 1892, and found the area ripe with possibility. Perceiving the opportunities, in 1903 he purchased the 600-acre San Marino Ranch, which became his estate and working ranch, and would later become the Huntington Library, Art Collections, and Botanical Gardens. It was the golden age of horticulture, with waves of newcomers, drawn by the mild climate, transforming the landscape with plants from all over the world.

Though the indigenous Engelmann and coast live oaks on his property were among his favorite plants, Huntington was keen to introduce and cultivate such exotic ornamental and edible plants as would likely thrive in the benign climate. Tropical fruits were a particular interest, and Huntington started California’s first commercial avocado orchard. He was also said to be among the first (if not the first) to grow cymbidium orchids outdoors in California.

Continuing this legacy, the Huntington Botanical Gardens has a long history of introducing new plants to horticulture in California and, indeed, the United States. Most of our introductions have been presented on a rather informal basis, but the Huntington does participate in two programs to introduce or promote new or little-known plants. The International Succulent Institute (ISI) was formed in central California in 1958 as a non-profit organization to serve as a source of “new, scientifically or horticulturally valuable [succulent] plant material not available through commercial sources.” One of the founders was Myron Kimnach, then curator at the University of California Botanical Garden at Berkeley and soon to become garden superintendent (later curator/garden director) at the Huntington. Originally an independent organization, the ISI has been housed and administered through the Huntington since 1989, and is now known as the International Succulent Introductions. Realizing a similar need for non-succulent plants, Pacific Plant Promotions (PPP) was formed in 2000 as a joint program of the Huntington Botanical Gardens, Rancho Santa Ana Botanic Garden, and the Pacific Horticultural Foundation (publisher of Pacific Horticulture). Through these programs, the Huntington has introduced several plants, such as Deppea splendens (April 2000 PPP), previously known in only a few botanical gardens and private col-lections, to a wider audience. Many new plants also make their way into California horticulture through our annual plant sales.

Agave attenuata ‘Boutin Blue’

Agave attenuata ‘Boutin Blue’

Early Introductions

Perhaps the most significant plant introduction from the Huntington (though few associate us with it) is the well-known houseplant Schefflera arboricola. Native to Taiwan and Hainan, where it is widespread in forests at a range of elevations, it grows as a shrub or climber from nine to twelve feet tall; it has a similar habit in cultivation. The Huntington obtained seed of S. arboricola in 1965 from the Heng-chun Tropical Botanic Garden in southern Taiwan. Four seedlings resulted and were planted in the gardens; all are still extant. Three were planted in two garden areas (the Café and the Mausoleum gardens) where they could develop their shrubby habit. The fourth was planted as a climber on an east wall of the Huntington Gallery, remaining there until renovation of the building in 2005 forced its removal. (This plant was boxed and saved for future replanting.) Additional plants have been subsequently grown from cuttings and planted elsewhere in the gardens, even thriving in the relatively tough environment of our parking lot. Recognizing the plant’s potential, garden director Myron Kimnach gave cuttings to Encinitas nurseryman Horace Anderson, who promoted it as a good houseplant. The story is that Horace “lost his shirt” on this plant in the first year, but the rest, as they say, is history. While in Taiwan in 1996 doing fieldwork with my Hungarian colleagues for the Dendrological Atlas project, I hoped to see S. arboricola in its natural habitat. I was to be frustrated until the last hour of our last day in the field, when I finally spotted one climbing a tree.

Among our most coveted, but most difficult to acquire, introductions is Dombeya cacum-inum. A pre-1950 accession of an unidentified species of Dombeya first flowered in 1965; upon flowering again in 1966, botanist Mildred Mathias determined it to be D. cacuminum. Plants of that early accession had died by 1978, but, meanwhile, we had also obtained seed of this species in 1968 from the Tsimbazaza Botanical and Zoological Park in Antananarivo, Madagascar. Called strawberry snowball for its large clusters of strawberry pink flowers in late winter, this stately tree is an improvement over the more commonly cultivated D. x cayeuxii and D. wallichii, which can be short-lived and brittle, and, after flowering, hold on to their blooms, which soon become brown and unsightly. In contrast, D. cacuminum drops its flowers after blooming, a decided advantage. However, this attribute also makes it challenging to propagate. Difficult from cuttings, it is more reliably grown from seed, which is not fully ripe until two to three months after flowering. It blooms for about a month in mid-winter, and if the weather is not too stormy, the spent blossoms hold on long enough for seed to mature. This usually occurs around May, coinciding with our busiest time of year in the garden, so it is easy to forget to collect the seed.

Salvia gesneriiflora ‘Mole Poblano’

Salvia gesneriiflora ‘Mole Poblano’

Mexican Explorations

Mexico is considered home to one of the world’s richest floras, much of it still to be explored and discovered. The Huntington has a long history of plant exploration there, dating back to William Hertrich’s tenure as Henry Huntington’s ranch superintendent. Perhaps the most notable of Hertrich’s collections was Mexican bald cypress (Taxodium mucronatum) from specimens in Chapultepec Park in 1912, although Francesco Franceschi of Santa Barbara is credited with introducing this species into the US in 1895. Today, several magnificent specimens from Hertrich’s collection grace the Huntington’s Rose and Lily Ponds gardens.

More recent expeditions south of the border took place in the 1960s and 1970s, primarily to study and acquire plants for the Huntington Desert Garden. Myron Kimnach started the Huntington Plant Sale in 1975, partly to fund this field work and partly to provide an outlet for plants—many new or little known—that exceeded the garden’s needs. Mexico’s renowned succulent flora yielded many wonderful treasures. Among these was a new form of Agave attenuata, collected in 1970 by Myron Kimnach and Huntington botanist Fred Boutin in Jalisco’s Sierra de Minantlan. Plants with strikingly blue foliage and an erect inflorescence were collected, contrasting with the typical green leaves and arching inflorescences of A. attenuata then in cultivation. The plants were grown in the Desert Garden and seed-grown offspring of these were offered through the ISI in 1984. Though thought to be a new botanical variety by noted agave expert Howard Scott Gentry, the plants were never formally named and were dispersed and sold under provisional names such as ‘Huntington Blue’ and ‘Nova’, the latter name published with the second ISI offering of this plant in 1990. However, in the June 2000 issue of the journal of the British Cactus and Succulent Society, Colin Walker renamed the plant ‘Boutin Blue’, stating that the name ‘Nova’ was invalid according to the International Code of Nomenclature for Cultivated Plants. Along with cacti and other succulents, many salvias were collected in Mexico, several still unidentified and potentially new species. In 1970, Kimnach and Boutin made two seed collections of Salvia gesneriiflora on Jalisco’s Volcán de Tequila, one from plants with the typical green calyx, one from plants with purple calyces. Progeny of both were eventually planted in the Subtropical Garden, and two selections were made from the purple-calyx clone: ‘Tequila’ has dark purple black calyces and inflorescence stems; ‘Mole Poblano’ has the same features but is more floriferous with a longer bloom season. Both become large shrubs, six to seven feet tall with an equal or wider spread, and have vivid red flowers in winter through spring, particularly cheerful during the winter holidays.

Dombeya cacuminum

Dombeya cacuminum

Two other Huntington salvia introductions have become established in the nursery trade throughout the US: Salvia ‘Purple Majesty’ and S. ‘Indigo Spires’. Both are considered tender perennials in USDA zones 7–8, where they die to the ground in winter. ‘Purple Majesty’ was the result of a cross made by Fred Boutin between S. guaranitica and S. gesneriiflora ‘Tequila’. One of the three offspring was selected and introduced around 1980. An herbaceous shrub, ‘Purple Majesty’ has open growth to three to four feet, with an eight- to ten-inch spike of royal purple flowers and dark purple calyces from spring until the onset of winter cold. ‘Indigo Spires’ was a chance seedling, found growing near purported parents S. longispicata and S. farinacea (both from seed collected by Boutin in Mexico and Texas, respectively); it was selected by Huntington horticulturist John MacGregor and introduced in 1979. It has herbaceous growth of three to five feet from a woody rootstock and one-foot-long spires of indigo blue tubular flowers. In our warmer California climate zones, it is evergreen and virtually everblooming.

Agapanthus ‘Huntington Blue’. Photograph by Clair Martin

Agapanthus ‘Huntington Blue’. Photograph by Clair Martin

Garden Surprises

Other Huntington introductions also originated as chance occurrences on our grounds; Prunus serrulata ‘Pink Cloud’ is one of the most distinctive. It originated before 1960 as a light-pink-flowered seedling from an open-pollinated, single, white-flowered P. serrulata. It is notable for reliably flowering in mildwinter areas, even near the coast. It typically blooms in February and March, with a cloud of soft pink blossoms with darker centers. ‘Pink Cloud’ flowering cherry has been in the nursery trade for several years now and is readily available, usually as high-grafted trees. Grown from cuttings on its own roots, it tends to be low branching and even bushy; we occasionally still offer plants thus grown.

Agave attenuata ‘Boutin Blue’

Agave attenuata ‘Boutin Blue’

Another chance occurrence, Penstemon ‘Apple Blossom’ was a selection made in 1969 from plants of unknown origin growing at the Huntington director’s residence. About two feet tall, it has a dense spreading habit and nearly year-round flowers with a white or pale pink tube and medium pink petal tips. Because some propagules were distributed before we named it ‘Apple Blossom’, it is sometimes still seen under the provisional name of ‘Huntington Pink’.

Some introductions get “branded” with our name, such as Agapanthus praecox subsp. orientalis ‘Huntington Blue’. It is a superior, large, dark-blue flowered agapanthus that has been on the Huntington grounds since the 1930s (original source unknown) and was named and introduced at our annual plant sale in 1979; we may still be the only supplier. On the other hand, Rosmarinus officinalis ‘Huntington Carpet’ is readily available in the nursery trade. This was a chance seedling of R. o. ‘Lockwood de Forest’ having pale blue flowers and a prostrate habit that makes an excellent ground cover to one-and-a-half feet high by eight feet across. Other Huntington-branded plants originated here, but were given names by others without our knowledge; we often do not know the details of the plants’ origins, making for a difficult situation when someone calls us to ask about one of them. We’re only too happy to share plants with others and lend our name to them, but it would be helpful if we were advised, so as to avoid future confusion. Particularly notable in this category are Artemisia ‘Huntington’, which has made its way across the country, and Juniperus horizontalis ‘Huntington Blue’. We can only speculate about the former, and haven’t a clue about the latter.

Prunus ‘Pink Cloud’

Prunus ‘Pink Cloud’

Plant Sales

Several of our introductions can perhaps be better categorized as plants that we may or may not have been the first to grow but that we popularized through our plant sales or were the original supplier to the nursery trade. Though we are still the only source of a few of them, some have made their way into the local and national nursery trade. I have been known to practically force plants and cuttings on colleagues visiting from nurseries or other botanic gardens, and several of these plants have become established in the California nursery trade. In a country as large and diverse as the US, documenting plant introductions is no easy task, and some of our introductions may not be well documented or even attributed to us. We are often amused by an out-of state nursery’s “new introduction” of a plant that we have been growing and selling for decades. As an example, in 1976 we received, from a source in Argentina, seeds of Aloysia virgata, a large shrub or small tree from Peru, Bolivia, Brazil, and Argentina with fragrant flowers during much of the year. A staple at our annual plant sales, long-time plant sale manager Shirley Kerins is a tireless promoter of it. Occasionally seen in California nurseries, we are still the main source, though it has recently appeared in a mail-order catalog from the Southeast, where it was identified as a new introduction from a recent expedition to Argentina. Though perhaps not having the romance of a foreign plant collecting expedition, we invite our colleagues from other parts of the country to visit California and see what is already growing here.

The late Fred Meyer shared my passion for Australian plants and, over the years, generously shared with us many new plants he imported from Australia. One of these was Westringia fruticosa ‘Morning Light’, given to us in 1986. After a few years in the Australian Garden, this low-growing variegated cultivar seemed like such a winner that no visiting colleague escaped from here without some cuttings; it is now well established in California nurseries and gardens. We believe we were the actual introducers of some other Australian plants, and, if anyone has information proving otherwise, I would be glad to hear it. In 1988, the Southern California Horticultural Society (then Institute) awarded its annual scholarship to Tom Kuykendall for the purpose of furthering his graduate studies in horticulture at the University of Western Australia in Perth. I arranged with Tom to obtain and send to the Huntington some Western Australian plants, which he duly did in 1989. Among those were Eremophila racemosa, obtained from Zanthor-rhoea Nursery, and E. nivea, obtained from Lullfitz Nursery (the latter a 2005 PPP offering). E. racemosa has proven to be an adaptable small garden shrub and has found its way into the nursery trade in both Arizona and California. Sometimes dubbed the Easter egg bush, the tubular flowers begin as yellow to orange buds, open bright pink, and age to purplish pink, with all stages present at any moment for a festive multicolored effect. Somewhat fussier but no less worthy a garden plant, E. nivea forms an open shrub of silvery-white, felted foliage and purple flowers in spring (see January 2005 Pacific Horticulture).

Salvia ‘Purple Majesty’

Salvia ‘Purple Majesty’

From both a practical as well as politically correct standpoint, our ability to obtain new exotic plants is becoming more difficult and may eventually prove impossible. Nonetheless, we still have some new introductions in the pipeline, and can focus efforts on hybridizing and selecting from our existing collections. Current hybridizing efforts focus on small aloes for containers as well as for gardens. A future PPP offering from the Huntington is expected to be Coprosma ‘Chocolate Sundae’, a selection from seed of C. brunnea obtained from the Christchurch Botanic Gardens (New Zealand) in 1987. Some of the resulting seedlings differed enough from true C. brunnea that the original seed was suspected to be of hybrid origin (coprosmas are known to readily hybridize). ‘Chocolate Sundae’ is a ground cover, with small chocolate-colored leaves, that flows over the ground like hot fudge on a sundae. If only the plant were as tasty as its namesake . . .