Asketanthera Woodson

Morales, J. Francisco, 2018, Studies in Neotropical Apocynaceae LIV: a synopsis of Asketanthera, Candollea 73 (1), pp. 7-17 : 8-11

Asketanthera Woodson in Ann. Missouri Bot. Gard. 19: 46. 1932.

Typus: Asketanthera calycosa (A. Rich.) Woodson.

Lianas, young stems herbaceous, becoming more or less woody with age; branchlets cylindric to subcylindric, with milky sap, pubescent to glabrate; interpetiolar colleters very small. Leaves opposite, petiolate, petioles without colleters, blades glabrous, glabrescent or variously pubescent, membranaceous, without colleters or domatia, not revolute. Inflorescence axillary, a few- to many-flowered cyme, usually variously pubescent, pedunculate, bracts foliaceous, well developed. Sepals 5, foliaceous, prominantly nerved, all more or less the same size and shape or subequal, free, with a single entire to variously lacerated colleter at the base of the adaxial surface. Corolla hypocrateriform with the indument distributed on five longitudinal lines, without corona or free corona lobes, the limb actinomorphic, 5-lobed, dextrorsely contorted. Stamens 5, included, anthers connivent and agglutinated to the style-head, anthers glabrous, the base auriculate, the auricles rounded to acute, filaments short, pubescent. Carpels two, united at the apex, style-head with a basal expanded ring. Ovules many, several-seriate; nectaries 5, each nectary lobed or entire, glabrous. Follicles 2, apocarpous, free, often remaining united at the tips for some time, dehiscing along the ventral suture, terete or subterete, membranaceous, continuous, pubescent to glabrate; seeds numerous, dry, rostrate, glabrous to sparsely pubescent, comose at the microphylar end.

Distribution. – Four species restricted to Cuba and Hispaniola ( Dominican Republic and Haiti).

[A-F: Figueiras 197, US; G-H: Eggers 4707, US] [Drawings: J.F. Morales]

[Fuertes 453, S] [Drawings: J.F. Morales]

Key to the species of Asketanthera

1. Corolla tube 63-80 mm; inflorescences 2-4-flowered; anthers 11-14 mm long.............................. 3. A. longiflora

1a. Corolla tube 11-21 mm; inflorescences 8-20-flowered; anthers 5.5-7 mm long.................................................... 2

2. Petioles 12-20 mm; peduncles (30-) 35-55 mm long......... ...............................................................2. A. dolichopetala

2a. Petioles 4-10 mm; peduncles 4-20 mm long...................3

3. Corolla tube 11-15 mm with lobes 9-15 mm; leaf blade with the base acute or attenuate.................. 4. A. picardae

3a. Corolla tube 15-21 mm with lobes 28-41 mm; leaf blade with the base obtuse to rounded ................. 1. A. calycosa