Ancistrocladus barteri
Ancistrocladus barteri in J. Linn. Soc., Bot. 30: 73. 1894 sec. Taylor & al. 20051
- Lectotype: Sierra Leone. Not located as to region: Mount Gonkwi, Duunia, Talla Hills, 16 Feb. 1892, G. F. Scott- Elliot 4860 (lectotype, designated by Airy Shaw (1950: 148), K; isotype, BM).
- =Ancistrocladus pachyrrhachis in Kew Bull. 1950: 149. 1950 syn. sec. Taylor & al. 20052
Notes
In floral characters, Ancistrocladus barteri is distinguishable from A. guineensis only by corolla aes-tivation, degree of dimorphism of filaments, and stamen dimensions, as outlined in the Key to Species above. These two species (or geographical populations) also seem distinguishable by leaf characters: numerous obvious small pits are found throughout the leaves of A. barteri, versus few to frequent but hardly visible small pits restricted to the leaf undersurface and sometimes also isolated zones on the upper surface of the leaves of A. guineensis. However, with very few collections of these species available at anthesis, the occurrence of in-termediate as well as convolute corolla aestivation in A. barteri makes their distinction somewhat tenuous. These two species are provisionally maintained here based on the characters noted above and their apparently allopatric geographic ranges, but their status will need re-evaluation when fruits are discovered for A. barteri. No fruiting collections can be confidently asso-ciated with Ancistrocladus barteri. Scott-Elliot (1894: 73-74) described the fruits briefly in his original description as "obpyramidale, 5-angulare, costis incrassatis, sine calycis lobis 15 mm. long, et 15 mm. lat." However, the specimen on which this description is based is unknown and may be among those treated here as A. abbreviatus. In his original circumscription of A. barteri, Scott-Elliot included several specimens that were subsequently excluded from A. barteri by Airy Shaw (1949), who referred most of them to his newly described species A. abbreviatus. Ancistrocladus abbreviatus does have fruits that correspond to Scott-Elliot's description. Scott-Elliot (1894) did not designate a type for Ancistrocladus barteri, but listed a set of syntypes. As noted by Gereau (1997), Airy Shaw later (1950) re-evaluated A. barteri, restricting its circumscription and selecting a lectotype, Scott-Elliot 4860 from Sierra Leone. Scott-Elliot (1894: 74) specifically listed under his A. barteri the Nigerian specimen Barter 1699, whose identity has been contro-versial. Airy Shaw later (1949) identified this as A. guineensis, Keay (1954) subsequently included it in A. abbreviatus, and it is here included in the newly described A. abbreviatus subsp. lateralis. This was the only Barter collection included by Scott-Elliot in this eponymous species, but Airy Shaw explicitly excluded this Barter collection from his circumscription of A. barteri without explanation. However, there are no nomenclatural grounds on which to overturn Airy Shaw's decision. Separately Tieghem (1903: 154) stated that Barter 1699 had characters that distinguished it from all other Ancistrocladaceae, and gave it the provisional name "Ancistrocladus barteri Tiegh." He explained his conclusion as follows: "C'est done au bien, tout au moins, une espece autonome, que je nommerai pour le moment A. de Barter (A. Barteri v.T.)." In the same article, Tieghem (1903: 155) also published the new genus Ancistrella Tiegh. with the single species Ancistrella barteri Tiegh., based on Barter 1699, and asserted that this second name was the one he intended to accept: ". . . on est con-duit a regarder cette plante comme le type d'un genre nouveau, que je nommerai Ancistrelle (An-cistrella v.T). Ce sera desormais PAncistrelle de Barter (Ancistrella Barteri v.T.)." Tieghem (1903) analyzed the leaf anatomy of Ancistrella barteri in great detail and must have derived his anatomical material from the specimen Barter 1699, which was distributed to P apparently with Scott-Elliott's name on it. In any case Tieghem, with his particular interest in Ancistrocladus, was probably aware of the publication of Scott-Elliot's name. Unfortunately, Tieghem (1903) was not always clear or conventional in his use of taxonomic nomenclature, so his intent is not entirely clear here. However, his use of his own initials with these names seems to indicate that his intent was indeed to separate these names from Scott-Elliot's usage. Therefore, Tieghem's work cannot be interpreted as a lectotypification of Scott-Elliot's name, and the names Ancistrocladus barteri Scott-Elliot and Ancistrella barteri Tiegh. are heterotypic and independent due to the lectotypification of Ancistrocladus barteri by Airy Shaw (1950). As circumscribed here, Ancistrocladus barteri is variable in leaf size and shape, inflorescence size, petal size, and filament length. However, the specimens included here are linked by a continuous range of variation in these features, as discussed below. In particular, the variation in leaf form can be generally separated into several rather well-marked groups. One group is characterized by relatively small, elliptic to obovate leaves that are obtuse to rounded at the apex and contracted in the basal portion to a narrowed, pseudopetiolate structure; specimens with such leaves have petals 6-8 mm long and the longer filaments ca. 2 mm long (these measurements are based on three flowering collections, apparently representing three plants). A second group is characterized by its often larger, oblanceolate leaves that are acute to acuminate at the apex and uniformly narrowed to an acute base; specimens with such leaves have petals 6-11 mm long and the longer filaments ca. 4 mm long (these measurements are based on six flowering collections, representing five plants). The shortest of these petal measurements, 6 mm, is found on the type of A. barteri, which has relatively long narrow leaves with shortly acuminate apices. Several collections of Ancistrocladus barteri comprise multiple sheets that sample various portions of the plants, and include a wide range of leaf sizes and shapes. In particular a wide range of leaf sizes and shapes, on both sterile and flowering branch-lets and ranging from relatively long and narrow to quite small and apically obovate and obtuse, is found in the multi-sheet collection Baldwin 5839 [K!, the type of A. pachyrrhachis; Baldwin 10984 is taken from the same plant (Airy Shaw, 1950), and shows the same pattern]. The smallest leaves have apparently been considered aberrant, but they are found subtending most of the inflorescences, and are also found on sterile branchlets (e.g., de Wilde 801, BR). A notable narrowing to a pseudo-petiolate leaf base is seen in /. G. Adam 23228 (MO) and Malaisse 14718 (MO), but these collec-tions have acute leaf apices and the second collection has petals ca. 9 mm long. One collection, Morton & Jarr 1 758 (WAG), has leaves that vary from apically obtuse to slightly acuminate and basally attenuate to pseudopetiolate, linking the two leaf forms. A similarly broad variation in leaf size and shape is found in A. letestui (e.g., Halle 3955, P). Ancistrocladus pachyrrhachis was described (Airy Shaw, 1950) based on two collections by Baldwin that were both taken from the same plant and both with infructescence axes from which the fruits have all fallen. These collections are notable in the relatively large inflorescences with the ultimate axes markedly prolonged and racemiform. However, they differ in no other way from collections of A. barteri, and the inflorescence size in specimens assigned by Airy Shaw to A. barteri actually varies quite widely and reaches a size only a little smaller than that of Baldwin's specimens of A. pachyrrhachis. Consequently, A. pachyrrachis is here considered a synonym of A. barteri.
Habitat
Lowland wet forests from sea level to 95 m, on coastal bluffs, along rivers, and in a laterite pit.
Conservation
With an EO greater than 20,000 km2 and existing in Cote dTvoire (i.e., Ivory Coast), Ghana, Guinea (i.e., Guinea-Conakry), Guinea-Bissau, Liberia, Senegal, and Sierra Leone: Least Concern; Cheek (2000: 881) proposed a status of Data Deficient (DD).
Description
Juvenile plants very slender saplings to 2 m tall, lacking hooked branchlets. Juvenile leaves with persistence unknown, oblanceolate, 36.7-59.6 X 8.4- 12.0 cm, L/W 4.4-5.0, at apex obtuse to acute, at base acute then attenuate then abruptly very shortly rounded or long-attenuate (i.e., pseudopetiolate), in life not seen, drying chartaceous, dull or shiny, dis-colorous, brown above, yellowish brown below; pits similar to those of adult leaves; midrib plane adax-ially, thinly prominulous to prominent abaxially, with terminal gland not found; secondary veins 12 to 17 pairs; secondary and tertiary veins prominulous adaxially and abaxially; margins plane to thinly revolute. Adult stems climbing to 15 m high, to 8 mm diam. [probably becoming larger but no data], with bark gray-brown, smooth or with shallow longitudinal fissures, bearing scattered leaves and lateral branchlets to 50 cm long, these branchlets bearing a terminal group of leaves, without hooks (e.g., Hall & Ake Assi GC-45772, GC) or with 1 to several hooks (e.g., Morton & Gledhill SL 1027, WAG); hooks recurved to spiraling, 6-25 mm diam. Adult leaves drying chartaceous to stiffly subcoria-ceous, rather shiny on both surfaces, in life disco-lorous, dark green above, light green below, drying at least a little discolorous, dark brown above, yellow-brown below; pits dimorphic, small pits frequent to dense on both surfaces (i.e., 1 to 4 per areole formed by tertiary veins), large pits 0.1-0.3 mm diam., circular, widely scattered on both sur-faces (i.e., several per leaf); midrib adaxially plane to shallowly sulcate, abaxially prominent, often terminating in a tiny gland; secondary veins prominulous on both surfaces; tertiary veins reticulated and prominulous on both surfaces; margins very thinly revolute; stem leaves with persistence un-known, elliptic to oblanceolate or narrowly obovate, 6.3-41.7 X 2.4-10.6 cm, L/W 2.6-4.6, at apex rounded to short-acuminate, at base cuneate to truncate; secondary veins 5 to 20 pairs, with submarginal vein situated 2-5 mm from margin; leaves at branchlet apices with persistence unknown, ob-ovate to elliptic or oblanceolate, 3.5-31.4 X 1.8- 9.4 cm, L/W 2.4-4.2, at apex rounded orobtuse to acute or acuminate with acumen to 15 mm long, at base cuneate to acute then abruptly and very shortly rounded, sometimes basally narrowly long-attenuate (i.e., pseudopetiolate); secondary veins 5 to 14 pairs, with intramarginal vein situated 3-6 mm from margin. Inflorescence lax, paniculate, lateral among leaves at apices of branchlets, without hooks, sometimes with bracteal leaves similar to adult stem leaves (e.g., Ake Assi 1 7146, MO; Bald-win 10984, MO; Merello et al. 1301, MO); peduncle 4.0-9.5 cm long, straight to curved; branched portion corymbiform, 5-15(-24) X 7-16 cm, branched 1 to 4 times dichotomously then subsequent axes racemiform; bracts ovate to triangular, 1-2 mm long, at apex acute to obtuse, at base obtuse, marginally hyaline and often erose, abaxially with a rounded gland covering V2-2A of surface; pedicels 1-4 mm long. Flowers all pedicellate; sepals 5, narrowly elliptic to elliptic-oblong, rounded and entire at apex, at base cuneate to obtuse and decurrent on ovary, green sometimes with translucent veins and/or red margins, external 2 or 3 sepals abaxially with 1 to 4 elliptic raised glands, adaxially appar-ently without pits, subequal, 2.5-4.5 X 1.5-3.0 mm; petals 5, convolute or rarely intermediate (e.g., Leeuwenberg2 709, WAG),o bovate, yellowish white or white tinged pink or sometimes pale violet in-ternally and orange externally, 5.0-11.0 X 2.0-2.5 mm; stamens 9 or 10 in apparently 2 whorls, white; filaments slender, dimorphic, the shorter 1.2-2.0 mm long, the longer 2.0-4.0 mm long; anthers 0.4- 0.7 mm long; ovary fully inferior, ca. 2 mm long; styles 3, 3.0-4.5 mm long, stigmas 0.2-0.5 X 0.5- 0.8 mm. Fruit not seen.