Dendrosicyos.

Dendrosicyos Balf.f.
Dendrosicyos I. B. Balfour, Proc. Roy. Soc. Edinburgh 11: 513. 1882.
Type: Dendrosicyos socotranus Balf.f., Schweinf. 243 (K, P).

The only perennial tree in the family, with a 3(-6) m high trunk that can be up to 1 m in diameter. The plant is monoecius with relatively few, pendent branches, the leaves are simple, petiolate with an ovate-cordate blade that is deeply pedately 4-6-lobed, prickly, the margin serrate, and a characteristic, unpleasant odor. The tendrils are lacking. The medium-sized flowers (2.5 cm in diam.) are produced in in pendent axillary fascicles. They are composed of a funnel-shaped receptacle-tube, five lanceolate sepals, and five linear-lanceolate, yellow and tomentose petals. The male flowers have three exserted stamens with straight thecae, which are inserted on the mouth of the tube. The pollen grains are medium-sized (polar axis c. 69 µm, equatorial axis c. 71µm), tricolporate and reticulate (Khunwasi 1998). The female flowers have an ovoid, smooth and rostrate ovary, a long and slender style with three bilobed stigmas and five staminodia. The fruit is cylindric, up to 4 cm long, rostrate, glandular setose and orange when ripe. It contains many compressed and c. 6 mm long seeds in an orange pulp.
The only species, D. socotranus I. B. Balfour, is endemic to Socotra, where it grows in shrubland communities. It is highly threatened by overgrazing, which reduces seedling survival.

Accepted species

Dendrosicyos socotranus Balf.f., Proc. Roy. Soc. Edinb. 11: 513, 1882 [as D. socotrana].

 

Literature

Baillon, M. H. 1885. Une nouvelle Cucurbitacée anormale. Bull. Soc. Lin. Paris 1: 441-442.

Khunwasi, C. 1998. Palynology of the Cucurbitaceae. Doctoral Dissertation Naturwiss. Fak., University of Innsbruck.

Olson, M. E. 2003. Stem and leaf anatomy of the arborescent Cucurbitaceae Dendrosicyos socotrana with comments on the evolution of pachycauls from lianas. Plant Syst. Evol. 239: 199-214.