Ancistrocladus guineensis
Ancistrocladus guineensis, Fl. Trop. Afr. 1: 175. 1868 sec. Taylor & al. 20051
- Holotype: Nigeria. Cross Rivers State: Calabar, 1859-1863, G. Mann 2234 (holotype, K; isotypes, GH, P).
- =Ancistrocladus uncinatus, Fl. W. Trop. Afr. 1: 196. 1927 syn. sec. Taylor & al. 20052
Notes
The name Ancistrocladus guineensis has been widely applied by previous authors to plants be-longing to various other species, but in particular to plants treated here as A. barteri. Part of the confusion may be due to the specific epithet, which in the modern usage of "Guinea" suggests that this name applies to plants from West Africa. However, the type of A. guineensis is from eastern Nigeria, and its range extends from there into Cameroon and Gabon. Ancistrocladus guineensis and A. barteri are similar in many features, and further study may show these taxa to represent extremes of continuous variation. However, there do appear to be some differences between them, as outlined in the Key to Species above and discussed under A. barteri, and they also appear to have disjunct ranges and therefore are provisionally separated here. Ancistrocladus uncinatus has long been separated from A. guineensis based on its smaller leaves, said by previous authors to be variously "6-8 cm long" (Hutchinson & Dalziel, 1927: 196) or "under 8 cm long" (Airy Shaw, 1950: 149). Some leaves on the isotype of A. uncinatus (BM) are as small as this, but others range to significantly larger. When these larger leaf measurements are included in the description of A. uncinatus, no differences are evident between this and A. guineensis. The isotype of A. uncinatus bears an inflorescence fragment with the ultimate axes becoming racemiform, as in A. guineensis, and one detached flower. This flower matches those of A. guineensis except it is about 20% smaller. However, this flower appears to be very shriveled and its measurements, therefore, are not completely reliable. Although Cheek (2000: 873) reported the petals as tomentose on the outer surface, this condition is not evident on the isotype. The leaves on the type collection of A. uncinatus are distinctive in being markedly narrowed toward the base, which gives it at first glance a different general appearance from most collections of A. guineensis; however, this distinctive shape is also found on occasional specimens of A. guineensis and A. barteri, and does not seem to be taxonomically informative.
Conservation
With an EO greater than 20,000 km2 and existing in Cameroon, Gabon, and Nigeria: Least Concern; with far fewer collections available from a much smaller geographic range, Cheek (2000: 877) proposed a status of Endangered (EN A2c).
Description
Juvenile plants unbranched or sparingly branched saplings to 3 m high. Juvenile leaves unknown. Adult stems climbing to 15 m high, main stems to 5 cm diam., with bark brown to purple-brown, smooth or with small shallow fissures, bearing some scattered leaves and also lateral branchets to 25 cm long, these each bearing 1 to several hooks and sometimes a terminal rosette of leaves; hooks recurved to spiraling, 9-24 mm diam. Adult leaves drying chartaceous to coriaceous, on both surfaces dull to shiny, in life not seen, when dry usually somewhat discolorous, dark brown above, lighter brown below, or sometimes concolorous and gray-tan on both sides; pits dimorphic, small pits sparsely scattered on abaxial surface, sparsely distributed and concentrated near midrib and margins on adaxial surface, large pits 0.3-1.0 mm diam., circular to oval, rare on both surfaces; midrib adaxially plane to shallowly sulcate, abaxially prominent, sometimes terminating in a tiny gland; secondary veins prominulous on both surfaces; tertiary veins reticulated, prominulous adaxially, nearly plane to prominulous abaxially; margins plane to shortly revolute; stem leaves with persistence un-known, elliptic to obovate, 5.5-23.1 X 2.6-8.8 cm, L/W 2.0-4.1, at apex obtuse to rounded, at base truncate to cuneate; secondary veins 4 to 11 pairs, with intramarginal vein situated 2-4 mm from mar-gin; leaves at branchlet apices with persistence un-known, oblanceolate to obovate, 7.2-33.0 X 3.0- 9.4 cm, L/W 2.3-4.8, at apex shortly and acutely or obtusely acuminate to obtuse or rounded, at base attenuate or abruptly narrowly contracted (i.e., pseudopetiolate); secondary veins 7 to 16 pairs, with intramarginal vein situated 2-4 mm from margin. Inflorescence lax, paniculate, lateral or subter-minal among leaves at apices of branchlets, along peduncle and primary axis occasionally with hooks (e.g., Jones & Onochie in FHI 16641, P) or bracteal leaves similar to adult stem leaves (e.g., Gereau et al. 5603, MO); peduncle 1.5-8.0 cm long, straight; branched portion corymbiform, 5-15 X 12-20 cm, dichotomously branched; bracts triangular-ovate, 0.8-1.6 X 0.5-1.0 mm, at apex acute to obtuse, at base obtuse, marginally entire, abaxially with a discoid gland covering ca. 1/2 the surface, occasionally also with 1 or 2 poorly defined pits near base; pedicels 2-5 mm long. Flowers all pedicellate; sepals 5, oblong to elliptic-oblong, rounded and entire at apex, at base truncate and shortly decurrent on ova-ry, light green tinged red-purple, abaxially some-times with 1 to 4 pit-like glands, adaxially with small pits, unequal, larger 3 sepals 3.5-5.1 X 1.4- 2.5 mm, shorter 2 sepals 3.2-4.2 X 2.0-2.9 mm; petals 5, imbricate, oblong-obovate, pale yellow tinged pink, ca. 8.1 X 3.2 mm; stamens 10 in 2 whorls; filaments slender, a little dimorphic, the shorter ca. 4.5 mm long, the longer ca. 5.0 mm long; anthers 0.8-1.0 mm long; ovary ca. 34 inferior, 1-2 mm long; styles 3, ca. 5 mm long, stigmas ca. 0.4 X 0.9 mm. Fruit turbinate; nut 5-8 X 3-6 mm, on sides longitudinally shallowly 5-ridged by de-current margins of accrescent sepals; persistent se-pal limbs spreading, papyraceous, dark red, un-equal, the larger spathulate to oblanceolate, 28-42 X 13-16 mm, the smaller oblong-spathulate, (5-) 12-16 X (4- )5- 6 mm; pericarp drying brown, coriaceous; seed not seen.
Phenology
In fruit in February and September.
The name Ancistrocladus guineensis has been widely applied by previous authors to plants belonging to various other species, but in particular to plants treated here as A. barteri. Part of the con-fusion may be due to the specific epithet, which in the modern usage of "Guinea" suggests that this name applies to plants from West Africa. However, the type of A. guineensis is from eastern Nigeria, and its range extends from there into Cameroon and Gabon. Ancistrocladus guineensis and A. barteri are similar in many features, and further study may show these taxa to represent extremes of continuous variation. However, there do appear to be some differences between them, as outlined in the Key to Species above and discussed under A. barteri, and they also appear to have disjunct ranges and therefore are provisionally separated here. Ancistrocladus uncinatus has long been separated from A. guineensis based on its smaller leaves, said by previous authors to be variously "6-8 cm long" (Hutchinson & Dalziel, 1927: 196) or "under 8 cm long" (Airy Shaw, 1950: 149). Some leaves on the isotype of A. uncinatus (BM!) are as small as this, but others range to significantly larger. When these larger leaf measurements are included in the de-scription of A. uncinatus, no differences are evident between this and A. guineensis. The isotype of A. uncinatus bears an inflorescence fragment with the ultimate axes becoming racemiform, as in A. gui-neensis, and one detached flower. This flower matches those of A. guineensis except it is about 20% smaller. However, this flower appears to be very shriveled and its measurements, therefore, are not completely reliable. Although Cheek (2000: 873) reported the petals as tomentose on the outer surface, this condition is not evident on the isotype. The leaves on the type collection of A. uncinatus are distinctive in being markedly narrowed toward the base, which gives it at first glance a different general appearance from most collections of A. gui-neensis; however, this distinctive shape is also found on occasional specimens of A. guineensis and A. barteri, and does not seem to be taxonomically informative