Hybrids containing Adenium crispum & swazicum Hybrids between these two species have been made by a few people. The expectations for primary (1st generation) hybrids: Adenium swazicum should contribute round flowers with solid, intense petal color, dark throats, and massive roots. Adenium crispum should contribute narrow leaves with white veins, and small, star-shaped flowers with nectar guides extending well onto the petals. A. crispum is heavily dominant in hybrids with A. "obesum ", so I expect it to do so in this hybrid group. These young plants show traits from both parents. A. swazicum shows in the nearly solid petal color and dark throat, and short anther tails. A. crispum influence is revealed in the nectar guides onto the petals, and the narrow leaves with white veins. I expect that mature plants will have massive caudex and roots. Mr. Vaghela named the cross Krishna as a group, not a cultivar name for one clone. Photos: Hiren Vaghela.

Hybrids containing Adenium " arabicum", "obesum", & crispum Crossing “arabicum” x “obesum ” plants with “arabicum” x “crispum ” plants creates a trifecta, my ideal adenium: medium-sized plants (three to five feet [90-150 cm] tall, from the crispum parentage) with comparatively large caudexes (from "arabicum " and crispum ), sturdy stems (from "arabicum"), and large flowers (three-plus inches [76+ mm] from "obesum ") that often have splashed petals (from crispum ). The plants are fast-growing and quite cool-tolerant; they don’t get root rot even if watered in winter. Many are evergreen and flower almost year round. Seedlings flower in a year or two. Cuttings root easily and produce caudexes in a few years. (Cuttings are more economical than grafting as is required of most “obesum” x crispum hybrids because of the former species' usually poor caudex development and the latter’s slow growth.) What more could a plant breeder ask for? This breeding line is my main focus now, and it appears that no other hybridizers are working with any "arabicum " interspecific hybrids. While these plants can still grow too large for the mass commercial market, their size can be limited by hard culture. See the superior hybrids page for more images and descriptions. Above two images: Adenium 'St. Elmo's Fire' is a typical example of complex hybrids containing Adenium "arabicum ", "obesum ", and crispum . The plant above is ten years old in a 16-inch pot, and is about two feet (60 cm) tall and three feet (90 cm) wide. See the gallery of superior cultivars for more hybrids in this line. Above: Adenium 'Nearly Perfect #777'. Above: Adenium 'Starbright'. Above: Adenium 'Radiant Dawn'. Footnotes

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Adenium crispum x "obesum" hybrids This hybrid line was a huge breakthrough in adenium breeding. There were a few such crosses in the early 1990s in California and possibly elsewhere, but even though the F1 plants had the petal markings of crispum, the usually small, twisted flowers didn’t inspire much enthusiasm. In 1999 I sent a cutting of A. crispum to a collector in Taiwan (I later named it ‘Famous Ancestor’ . He propagated it and shared it with other growers. This species is difficult in hot, humid climates. The clone died out within a couple of years, but not before hybrids were made with A. “obesum”. First generation (F 1 ) hybrids inherit from "obesum" vigorous vegetative growth and large, colorful flowers. The crispum parent often contributes a substantial caudex, and quilled flowers with strong nectar guides that extend to the petal tips. Unfortunately, both parents tend to contribute weak stems. Plants of this line are usually slow-growing, taking at least 5 years to develop their character (in Arizona; they grow much faster in more tropical climates). After several generations the Taiwanese breeders had eliminated the quilled petals and created plants with large flat flowers exhibiting bold petal markings. The nectar guides on the petals often morph into bold blotches and stripes. All flowers with such petal markings are descended from A. crispum , and probably from 'Famous Ancestor'. By 2008 there were millions of plants and hundreds of stunning named cultivars all over Asia. The plants in this group are mostly small to medium-sized and slow-growing, with modest caudexes (about 2 feet [61 cm] tall and wide); but some are “obesum” -sized (3 to 4 feet [91-122 cm]). Only the best clones have sturdy stems; most need pruning every few years to maintain a neat form. Superior clones flower profusely throughout the warm season. Both parent species are very cold-sensitive, but many of the complex hybrids (second generation and beyond) are resilient as long as they’re kept dry during winter. Almost all cultivars on the market are grafted. See the superior cultivars page for a big gallery of these hybrids. Adenium ' Harry Potter ' was the first crispum-"obesum " hybrid with fairly flat petals and bold markings. The nectar guides have become blotchy stripes. It was created in Taiwan by C.F. Chang in 2003, only 4 years after the introduction of A. crispum . A first-day flower is at left; a week-old flower at right. A few more early crispum-"obesum " cultivars. Left: Adenium 'City' from Taiwan is an example of a flower with strong contrast between the background and the nectar guides. Below: New and older flowers of 'Star of Taiwan' Below: 'Classical' has bold blotches overlain by even bolder lines. Created by H.C. Chen. Footnotes

Adenium oleifolium Stapf Adenium oleifolium occurs in South Africa and extreme southern Botswana. It is the smallest species in the genus. The caudex is subterranean, the stems are scarcely succulent, and rarely reach a foot tall. Plants in cultivation have small flowers are usually pale pink, with yellow throats and prominent red nectar guides. The anther appendages are just shorter than the tube, or may be slightly exserted. Wild plants come in a wide range of sizes and colors from white through pink to dark red. Plant and foliage of A. oleifolium . The plant is in a 6-inch pot and is about 6 years old. Flower of A. oleifolium . Note the yellow throat and moderately long anther appendages. A. oleifolium selected for darker flower color. Three seed-grown plants of A. oleifolium, several years old. Nectar guides may extend partway onto the petals. Those of A. crispum usually extend much farther toward petal tips. The petals are often narrow, but not as quilled as those of A. crispum . Leaves of A. oleifolium are longer and narrower than those of A. crispum , and lack the white veins. Photos: David Palzkill. Adenium oleifolium in the Wild A population of A. oleifolium near Uppington, Northern Cape, South Africa. The flower collection at right shows some of the variation at this locality. Variable traits include flower size, petal color and width, presence and prominence of nectar guides, and length of anther appendages. The variation is much greater than in any other Adenium taxon that I know of. Photos: Dawie Human. Left: An old plant of A. oleifolium collected from the wild . In nature the caudex was below ground. Photo: Robert H. Webb. Back to Top Footnotes

Adenium multiflorum Klotsch Adenium multiflorum is native to Mozambique and Zimbabwe. Wild plants range from scraggly understory shrubs to erect shrubs more than 8 feet tall. There is usually no distinct caudex, but the roots and stems become quite thick in older plants. It has the second largest leaves in the genus (after A. boehmianum ). Flowers are borne in profusion during winter when the plants are leafless. Plants have an obligate winter dormancy, and seem to require a cold (but above freezing) winter to stimulate flowering. The diagnostic features of this species are the white flowers with narrow red edges that bloom in winter, and the anther appendages that are exserted well beyond the throat that has prominent nectar guides. If your plant has picoteed flowers that bloom in other seasons when in leaf, it is not A. multiflorum . This species is not widely grown. The likely reasons are its slow growth and the need for a cool fall with strong winter light to flower well. Moreover, most people are not shopping for tropical plants during winter. Left and above: Adenium multifllorum flowers only in winter while leafless. This plant, 'MAD 110', is ten years old. Above: Flower of A. multiflorum 'MAD 110' Note the exserted anther appendages. The broad leaves of A. multiflorum . Only those of A. boehmianum are larger. Left and above: Caudex and flower of A. multiflorum 'Gus Spartas'. The plant was grown from a small seedling collected in Zimbabwe in 1998. The flowers of this plant have particularly wide and bright margin. Left and Above: A. multiflorum 'MAD 1', my first accessioned adenium cultivar. The plant in the photo is 29 years old. Above: A. multiflorum with a narrow picotee. Collection of Ashish Hansoti. Adenium multiflorum in the Wild Above: John Bliznak next to an Adenium multiflorum in Limpopo National Park, Mozambique. (The plant had been transplanted to a ranger station.) Photo: John Bliznak Above: Adenium multiflorum recently imported from Mozambique. Photo: John Bliznak Above: Adenium multiflorum in Thornybush Game Reserve, Mpumalanga, South Africa. After wet winters this species may flower with persistent leaves. (In biology there is an exception to every rule!) Plant and flowers of A. multiflorum in Kruger National Park, Mpumalanga, South Africa. This specimen was transplanted to a display garden at the Paul Kruger entrance gate. Photos: Sheryl Hayes. Most plants of A. multiflorum in Kruger N.P. are scrawny understory shrubs, probably because they're trampled by wildlife. These flowers lack a sharp red edge. Left and above: Plant and flowers of A. multiflorum at the entrance to the lodge at Thornybush Game Reserve, Mpumalanga, South Africa. Back to Top A gorgeous specimen of A. multiflorum , location unknown. Photo: Frandsen. [Lost contact; please help] Footnotes

Adenium boehmianum Schinz Adenium boehmianum is closely related related to A . swazicum , and occurs on the other side of southern Africa in Namibia and southern Angola. It is an erect arborescent shrub, usually with barely succulent stems and only modestly swollen roots. In the northern end of its range it develops thick conical trunks. The leaves are the second largest in the genus. The flowers have broad petals that usually overlap, and are borne from late summer into early winter. This species shares a diagnostic trait with A. swazicum : petals are of uniform pink with no fading toward the dark throat, and very short anther appendages. A. boehmianum is uncommon in cultivation. A. boehmianum at the Huntington Botanical Gardens. The plant is about six feet tall. A. boehmianum flowers are usually circular in outline. Notice that the petal color does not fade toward the throat. Flowers and foliage of A. boehmianum . Flowers and foliage of A. boehmianum . Right: An example of pink flowers of A. boehmianum. Photo: Cheryl Acford Adenium boehmianum in the Wild Adenium boehmianum in Namibia. Photo: Dan Mahr Adenium boehmianum in Namibia. Photo: Dan Mahr Adenium boehmianum in Namibia. This one has a well developed conical trunk. Photo: Dan Mahr Adenium boehmianum in Namibia. Photo: Dan Mahr Adenium boehmianum in Namibia. Photo: Dan Mahr Adenium boehmianum in Namibia. Photo: Robert H. Webb Adenium boehmianum at Ojihipa, Namibia (Angolan border on the Kunene River). Photo: Ernst Van Jaarsveld. Flowers of Adenium boehmianum in Namibia on the Kunene River near Epupa Falls. Photo: Ernst Van Jaarsveld. Adenium boehmianum in northern Namibia, exhibiting a splendid succulent trunk. Photo: Ernst Van Jaarsveld. Adenium boehmianum near Okabadjia, Namibia. Photo: John Lavranos. Back to Top Footnotes

Contribute Photos and Other Information Please help add to our knowledge about Adeniums. Criteria for contributing images and other information to this website Contributions of photos and information about adeniums are welcome. Contributors will be gratefully acknowledged. Please pay careful attention to the different goals: COMMENTS, CORRECTIONS, AND ADDITIONAL INFORMATION This fo rm is for submitting text and links to information sources. The latter is important: If the information is not your personal knowledge, please document where you obtained it - the first-hand source (personal communication to you), or a published article or website link. PHOTOS Use this form to contribute photos of wild plants, or cultivars that are substantially different from what is already on this site. A. Wild adenium plants : There is very little detailed information about the geographic distribution of adeniums. (There are only about 200 herbarium specimens from all of Africa and the Arabian Peninsula.) It’s also known that their natural variability is much greater than what is represented in cultivation. Plants seem to be distributed in isolated populations, and some of the wild plants that I have seen photos of are diff icult to assign to a known taxon . To further our collective knowledge of this beautiful genus: 1. When possible, please include images of the plant in habitat , a close-up of the plant (s), and close-ups showing the leaves, flowers, and/or fruit . 2. Photos of multiple specimens are desirable for each locality to show the local variability. (For example, both shrubby-dwarfs and arborescent A. “arabicum ” can grow in the sa me locality. Flower color and shape can also vary greatly.) 3. Provide at least fairly precise locality data . -For example, “Saudi Arabia” is not useful, -while “southwest of Sanaa, Yemen” and “Jabal Shada, S. Arabia” are okay, and -“hills near south end of Lake Eyasi, Kenya” is good information. 4. Plants that are not along major roads are especially valuable. 5. Plants that are very different from what's typical of the region are also treasured. For example, the plants of "obesum"(?) near Lake Eyasi , Kenya, with flowers that look like those of swazicum; or "somalense nova", scattered populations among "obesum" territory. B. Cultivars : Acceptance of cultivars is more narrow. This website is not intended to be an encyclopedia of named adeniums. There are many thousands, most of which are no longer in existence. Criteria for addition: 1. It stands out among the multitude of adeniums in at least one major trait… 2. Or it is historically important , e.g., as the founder of a major breeding line. 3. And it is substantially different from other cultivars already on this website. 3. It has been propagated and distributed to others, at least locally. C. In all cases, please send large photos , at least 1500 px or 2 MB, up to 15 MB. Comments, Corrections, and Additional Information. First name Last name Email Write a message Upload File Upload supported file (Max 15MB) Submit Thanks for submitting! Contribute Photos Your Name Email Category of contribution * Required Wild Plant Cultivar For Wild Plants Location (specific as possible) For Cultivars Parentage (if known, e.g., arabicum x obesum, or arabicum 'Shada' x obesum 'Dazzler') Distinguishing Traits* Proposed cv. name Creator (if known), or Place Obtained Upload File Upload supported file (Max 15MB) Submit Thanks for contributing! Adenium 'National Beauty'

Publications Taxonomy article Adenium: Sculptural Elegance, Floral Extravagance Dimmitt, Joseph, & Palzkill 2009 Adenium Taxonomy and Nomenclature Dimmitt & Edwards 2021 Adenium Taxonomia y Nomenclatur a Translated by Osmar Barboza (unpublished) Adeniums (Desert Rose) in Cultivation Dimmitt 2022 Adenium Culture in Hot, Arid Climates Characteristics of Adenium Species & Hybrids

Adenium "obesum" x swazicum hybrids Adenium "obesum" x swazcium hybrids are probably the first intergeneric crosses made in the genus. The primary hybrids (first generation, aka F 1 ) have fairly consistent traits and are usually quite beautiful. The plants are well-branched shrubs, but usually with weak stems that need hard pruning to mainta in a neat, upright form. The swazicum parent often contributes a large caudex or swollen roots. The “obesum” parent contributes large flower size and a wide range of colors. The swazicum parent intensifies the flower color (if the parents are dark) and transmits uniform petal color (i.e., it doesn’t fade toward the throat as in all other species except A. boehmianum). F 1 hybr ids also have dark red or black throats. The primary hybrids are pollen-sterile, so second generation (F 2 ) crosses are not possible. F 1 plants can be used as seed parents and back-crossed to one of the parent species, but most offspring are weak. Because of these problems, complex A. swazicum hybrids (second generation and beyond) are rare. See the superior cultivar page for a gallery of the best. Above left: a flower of 'Crimson Star ' (bottom) with its parents A. "obesum " 'Red Everbloomer ' (left) and A. swazicum 'Boyce Thompson '. This old scanned transparency is oversaturated. The photo above right is closer to 'Crimson Star's' color. Notice the centripetal fading of the petals of the "obesum" parent, and the solid color and characteristic dark throat of the hybrid. A 10-year-old cutting-grown 'Crimson Star '. This cv. has thick, sturdy stems and roots, but they develop slowly. Footnotes