Adenium somalense var. somalense

Adenium somalense var. somalense

A huge specimen Adenium somalense var. somalense; this one is at the December show in Bangkok and for sale for about US$25,000 !

A robust, tall and fast growing species. Makes big plants quickly and should be a good landscape item in frost free areas. Very fecund and crosses freely. Even more than A. multiflorum this species is mixed in almost all Adenium selections world wide. One common trait that it leaves is its progeny are the strong red lines going down the throat. We discarded our plants a long time ago, in an effort (only partly successful) to maintain a relatively pure strain on A. obesum for seed production. This was necessary when we grew all our plants together but I now regret it- they do form very nice specimen plants.

Adenium somalense var. crispum:
A subspecies discovered relatively recently, it is very different from the one above. My own experience with the species is limited to some cuttings from Mark Dimmit in USA and a few seedlings from Arid Lands, all but one of which died (possibly due to a reaction to the fungicide Mancozeb). What strikes one is the compactness of the plant, its very distinctive, narrow marbled foliage and the heavily marked flowers.

An Adenium somalense var. crispum clone from Mark Dimmit in USA.

The petals are twisted and curled in all the clones I have seen (hence the specific name) and it is dominant in its hybrids. It does bring patterns never seen before to its hybrids and opens up frontiers breeders had not imagined possible. Only time will tell where breeding efforts with this species will take us.

Adenium somalense Baif. f. occurs from Somalia south through the Rift Valley into Kenya and Tanzania (Rowley, 1983). The leaves arc 5 to 10cm long by 18 to 25 mm wide (2-4" by 0.75- 1"), bright green and usually with white veins. In habitat the most conspicuous form is the nominate variety somalense, a small tree to 15 feet tall with a very wide-based, distinctly conical caudex (Fig.11). The flowering branches are very thin and spreading to pendent. These giant-caudiciform populations occur in Somalia and northwestern Kenya. In most of Kenya they are shrubby with smaller caudexes, apparently from intergrading with A.obesum, which occurs on the coastal side of that country.

The flower is smaller than that of A.obesum, usually less than 5 cm (2") in diameter with narrower, pointed petals and prominent nectar guides that may extend slightly beyond the pubescent throat onto the petals (Fig.15). The flower color varies from pink to deep red, and, as in A. obesum, the color fades toward the throat. The flowering period of cultivated plants is usually from autumn through early summer but is considerably influenced by culture.

Adenium somalense is available in cultivation and easy to grow. Nearly all the plants are of the shrubby, presumed intergrade with A.obesum. This species has an obligate dormancy, usually beginning in November or December in Tucson. Plants do not releaf until flowering is past its peak in late spring.

In 1991 Dimmitt obtained seeds from an arborescent population in northwestem Kenya. The plants are extremely vigorous; seedlings produced mostly unbranched stems to six feet tall in a single growth spurt lasting 18 months. During the second and third growing seasons the plants scarcely increased in height, but the trunks thickcned substantially and grew numerous thin, ascending to horizontal flowering branches (Fig.13).

Adenium somalense var. crispum

Adenium somalense var. crispum Chiov. is dramatically different from the nominate (first-described, i.e., the arborescent) variety and its intergrades with A.obesum. The plants are dwarfs with napiform (turnip-shaped) subterranean caudexes (Fig.14). The relatively thin roots originate almost exclusively from the top of the caudex, whjch is just below the soil surface, very unlike the arborescent form's thick, succulent roots that radiate from the base of the broad, above-ground caudex. The few above-ground stems are erect to ascending, scarcely succulent, and rarely more than a foot tall (Fig.18). The leaves are narrowly linear, usually strongly crisped (wavy-margined), and prominently white-veined.

The flowers of variety crispum are also distinctive (Fig.16). Compared to the arborescent variety, they have larger throats and smaller, narrower, white to pinkish petals. The margins of the squarish petals are often curled downward (quilled). The pink to red nectar guides in the throat may extend halfway to the tips of the petals, giving the flowers a distinctly striped aspect. In some plants the petals are solid red (Fig.17). Flowering in cultivation is sporadic; it seems to be most profuse during winter dormancy but may extend well into summer. Seedlings can flower in less than two years when only 6 inches tall.

This variety occurs in the same area as A.somalense somalense but apparently does not intergrade with it (Gerald Barad and Seymour Linden, pers. comm.). John Lavranos (pers. comm.) considers tbe two to belong to the same taxon. The variety crispum grows slowly in cultivation; it takes about five years to produce a specimen with its characteristic, though still small, caudex. The caudex can be exposed above the potting medium to create charismatic bonsai-like treelets (the base can produce roots in cultivation).

Fig.11. Adenium somalense var.somalense, Lake Baringo, Kenya. The conical caudex is diagnostic. Photo: Thomas A.Wiewandt.

Fig.12. Adenium somalense var.somalense east of Bargal, Somalia Photo: Myron Kimnach.

Fig.14. Collected plant of Adenium somalense var.crispum. In habitat the caudex would be underground. Stubs of the original feeding roots can be seen ariund the top of the caudex.

Fig.13. Three yera-old, six-foot-tall sapling of Adenium somalense somalense in cultivation from seed collected in northwestern Kenya. Note the incipient swelling of the entire trunk, which occured rapidly in the fall of the third season.

Fig.16. Flowers of Adenium somalense var.crispum, a selected clone with brighter than average color and only slightly quilled petals.

Fig.15. Flowers of a cultivated Adenium somalense somalense from northwestern Kenya.

Fig.17. Adenium somalense var crispum, red-flowered plant with nonquilled petals north of Mogadishu, Somalia. Photo: Gerald Barad.

Fig.18. Adenium somalense var.crispum. road to Warshak, Somalia. The caudex is typically underground, as (not) seen here. Photo: Myron Kimnach.

Family:	Apocynaceae
Habitat:	Somalia, Kenya, Tanzania
Soil:	Mix
Water:	Medium
Sun:	Maximum
Thickness:	50 centimetres
Height:	5 meters
Flower:	Dark Pink
Reproduction:	Seeds/Cuttings
Pop names:	-
Synonyms:	-
Got it from:	-
Year:	-

It is found in Somalia, Kenya and Tanzania, growing in a well drained soil with some water and lots of sun. It will grow up to 50 centimetres in diameter, and the stems will grow up to to five meters in height. The flowers are dark pink.