Ancistrocladus robertsoniorum

Primary tabs

Ancistrocladus robertsoniorum

Ancistrocladus robertsoniorum J.Léonard in Bull. Jard. Bot. Belg. 54: 466, f. 1. 1984 sec. Taylor & al. 20051
    • Holotype: Kenya. Coast Prov.: Kwale Dist., Buda Forest, 60 m, 7 Sep. 1983, Mrs. S. A. Robertson 3687 (holotype, BR; isotype, BR, K not seen).
  • 1. Taylor, C. M., Gereau, R. E. & Walters, G. M. 2005: Revision of Ancistrocladus Wall. (Ancistrocladaceae). – Annals of the Missouri Botanical Garden 92: 360-399


Leonard (1984, 1986) noted that unlike other Ancistrocladus species, the stamen number of this species varies and sometimes ranges to as many as 15 stamens, with the number of whorls of filaments also variable; we have not confirmed either of these observations.

Distribution (General)

Southeastern Kenya.


With an EO of less than 5000 km2 and with a distribution limited to three sites in coastal Kenya, which support vigorous populations but are under threat from mining and illegal logging, and already listed as potentially threatened (Gereau & Luke, 2003): Endangered (Blab); Cheek (2000: 878) reported an assessment of Critically Endangered.


Juvenile plants unbranched or sparingly branched saplings to 4 m high, lacking hooked branches until late in development. Juvenile leaves somewhat crowded near apex of stem but not borne in rosettes, oblanceolate, 43.5-55.0 X 9.1-10.3 cm, L/W 4.7-5.3, at apex obtuse to acute, at base attenuate, drying chartaceous to subcoriaceous; pits dimorphic, similar to those of adult leaves; midrib adaxially slightly to strongly raised, abaxially prominent, terminal gland not found; secondary veins 19 to 27 pairs; secondary and tertiary venation adaxially prominulous, abaxially more strongly so; margins plane to thinly revolute. Adult stems climbing to 15 m high, to 3.5 cm diam., with bark dark brown, roughened, bearing scattered leaves and lateral branchlets to 25 cm long, these each bearing 1 to several hooks and sometimes a terminal cluster of leaves; hooks recurved to spiraled, 9-17 mm diam. Adult leaves drying chartaceous, on both surfaces matte to rather shiny, in life (pers. obs., CMT, MO greenhouse) and when dry discolorous, dark green above, yellow-green below; pits dimorphic, small pits moderately to densely distributed on both surfaces though sometimes denser on the adaxial surface, large pits circular, 0.2-0.4 mm diam., scattered on abaxial surface; midrib adaxially plane to distinctly raised, abaxially prominent, terminating in a tiny gland; secondary veins prominulous on both surfaces; tertiary veins reticulated on both surfaces; margins thinly revolute; stem leaves with persistence unknown, narrowly obovate-elliptic, 18.4- 50.0 X 5.3-10.2 cm, L/W 3.3-4.5, at apex obtuse, at base attenuate; secondary veins 14 to 24 pairs, with intramarginal vein not evident; leaves at branchlet apices with persistence unknown, ob-ovate-elliptic, narrowly elliptic, or oblanceolate, 6.5-30.0 X 2.0-7.5 cm, L/W 3.0-4.4, at apex acute to obtuse and sometimes very shortly acuminate or rounded to shortly emarginate, at base attenuate to acute and tapered then sometimes shortly abruptly rounded; secondary veins 10 to 25 pairs, with intramarginal vein 0-1 mm from margin. Inflorescence lax, paniculate, lateral among leaves at apices of branchlets, without hooks or bracteal leaves; peduncle 1.0-4.5 cm long; branched por-tion corymbiform, 4-11 X 5-15 cm, dichotomously branched; bracts ovate, 1.0-1.7 X 1.0 mm, at apex acute and fimbriate, at base obtuse, abaxially eglandular; pedicels 5-12 mm long. Flowers all pedicellate; sepals 5, elliptic to elliptic-oblong, at apex and base rounded, green sometimes tinged red near apex, marginally entire to sparsely ciliate, abaxially eglandular, sometimes both surfaces with small pits, subequal, 4.0-7.0 X 3.0-4.0 mm; petals 5, convolute (e.g., Luke 3343, MO; called "imbricate" by Leonard, 1986), obovate, greenish cream or yellow to buff or white sometimes tinged with pink, 5.0-7.0 X 3.4-3.6 mm; stamens 10 in 2 whorls [10 to 15 arranged in 1 or 2 whorls, Leonard, 1986]; filaments rather stout, dimorphic, the shorter 1.0-1.2 mm long, the longer 1.5-2.0 mm long; anthers ca. 0.7 mm long; ovary partially inferior, ca. 1.5 mm long; styles 3, ca. 3 mm long, stigmas ca. 0.5 mm long. Fruit turbinate; nut 5-8 X 5-6 mm, on sides longitudinally shallowly 5- ridged by decurrent margins of accrescent sepals; persistent sepal limbs spreading, chartaceous, elliptic-oblanceolate to spathulate, unequal, continuously grading in size, the largest 23-50 X 5-15 mm, the smallest 10-20 X 4-8 mm; pericarp drying chestnut brown; seed obconical, 3-4 X 4-5 mm, whitened.


Moist evergreen coastal forest at 25-300 m.


Collected in flower and fruit in November.