Inversodicraea feika Cheek, 2017

Tchouto, P. & Burgt, X. van der, 2017, A synoptic revision of Inversodicraea (Podostemaceae), Blumea 62 (2), pp. 125-156 : 143-145

24. Inversodicraea feika Cheek , sp. nov. — Fig. 2 , 3

Differs from all other species of Inversodicraea which have scale-leaves dense on the spathellae-bearing spur shoots and sparse or absent on the main shoot, in that the ovary and fruit are strongly laterally flattened and not cylindrical.Most similar to Inversodicraea adamesii , e.g., in fruit having only 6 longitudinal ribs,but differing in that c. 90 % of the scale-leaves are entire (not 90 % 3-lobed). Unique in the genus is that the styles are narrowly triangular in side view ( Fig. 2f ), resembling those of Dicraeanthus , not subulate, filiform or botuliform. — Type: Feika 146 (holotype K; isotypes BR, EA, FBC n.v., G, K, LISC, MA, MO, P, PRE, S, SL, US, WAG, Z), Sierra Leone, Western Area, Port Loko District, Port Loko, N8°45'29.0" W12°47'10.0", near bridge across Port Loko river in Port Loko town, 10 m alt., fl., fr., 17 Dec. 2010.

Etymology. Named in honour of Mr. Abdulai Feika of the National Herbarium of Sierra Leone (SL) at Njala University. He is the collector of the only two known specimens of the species.

Perennial herb, long stems streaming in the water, 15–80 cm long, terete, 1.5–2(–3) mm diam along most of their length, internodes 1.5–3 cm long in the proximal 1/2–3/4, decreasing to 0.7–1.5 cm long in the distal portions, sometimes with 1–3 principal branches. Root horizontal, terete, stolon-like, 0.6–1 mm diam, extending at least 5 cm long or more, internodes 2.5–7 mm long, nodes bearing opposite leaves which subtend fertile, leaflet-clad spur shoots ( Fig. 2c–d ) which can develop into erect highly branched candelabra-like stems c. 5 cm tall ( Fig. 2a (upper portion) and Fig. 2b ) and/or long sparingly branched stems. Lateral stems 0.8–7 cm long, usually regularly spaced along the principal stems, arising 1–4 mm below (and later than) the long ribbon-like leaves, scale-leaves and flowers at the nodes. Leaves ribbon-like, (0.7–)3–5(–7) cm long, 0.6–1.5 mm wide, 1–4-dichotomously branched, strongly dorsiventrally flattened (ribbon-like), apices acute. Scale­leaves more or less confined to the short spur shoots, 13–23 scale-leaves per shoot, spirally inserted; acicular, ascending, 0.2–0.3(–0.4) by 0.15 by 0.1 mm, apex acute to obtuse, entire, or rarely (1–2 in 10) with a lateral lobe c. 0.05 mm long. Spathellum cylindrical, substipitate 3.5–4(–4.2) by (1–)1.2–1.3(–1.4) mm apex rounded-obtuse, dehiscing irregularly at apex. Pedicel 7–8.5 mm long, 0.5 mm diam at base, narrowing towards the apex. Tepals 2, opposite stamen, narrowly oblanceolate, (0.9–)1.3–1.5 by 0.1 mm, minutely papillate. Androecium of 2 stamens, nearly as long or slightly longer than the ovary; united filaments 1–1.3 mm long (3 mm in fruit), free filaments 1.3–1.5 mm long (2 mm in fruit); anthers 4-celled, oblong, 0.9–1 by 0.5 mm. Pollen in dyads, 70–75 by 37–42 µm, the two grains each subspheroidal. Gynoecium with gynophore 1–1.1 mm long (2.5 mm in fruit). Ovary unilocular, oblong-elliptic in side view, 1.3–1.8(–2.2) by 0.6–0.8 by 0.4–0.5 mm. Styles erect, narrowly triangular, 1.2 mm long, 0.2 mm wide at base. Fruit oblong-elliptic, strongly laterally flattened, 2.5 by 0.9 by 0.6 mm, with 6 longitudinal ribs, ribs pronounced, each projecting 1.0– 1.5 mm; sutures not pronounced, dehiscing by a single suture. Seeds oblong-ellipsoid 0.2–0.25 by 0.1–0.12 mm.

Distribution — Sierra Leone, Port Loko.

Habitat & Ecology — On rocks in rapids of river, with I. ledermannii , in the evergreen forest zone; 10 m altitude.

Conservation — Known only from one location within Port Loko town limits, at two sites on the river locally known as the Gbankasoka. The AOO is estimated as 1 km 2. Threats observed are pollution of the habitat from clothes washing (Ben Pollard pers. comm. to M. Cheek 2010) and bridge construction for iron ore transport (Lebbie pers. comm.). Further, a micro-hydroelectric project is planned for the site. Therefore, I. feika is here assessed as Critically Endangered, CR B2 ab(iii). Port Loko in the most populous district in Sierra Leone after Freetown's Western Areas District.

Additional specimens. SIERRA LEONE, Western Area, Port Loko District, Port Loko, N8°45'29.0" W12°47'10.0", near bridge across Port Loko river in Port Loko town , 10 m alt., fl., fr., 17 Dec. 2010, Feika 146 (holotype K; isotypes BR, EA, FBC n.v., G, K, LISC, MA, MO, P, PRE, S, SL, US, WAG, Z) ; ibid., fl., fr., Mar. 2010, Feika 78B (K, SL n.v.) .

Notes — Inversodicraea feika is one of the most completely known species of the genus thanks to the two collections of Feika made by Mr. Feika and his associate collectors Ben Pollard, Sue Frisby, and Xander van der Burgt.

It has been collected in the reproductive state in mid dry season (March, Feika 78B), when it produced spathellae from the stolons and short (5 cm tall) candelabra-like stems, and in December at the end of the wet season when long streaming stems and leaves were present as well as spathellae ( Feika 146).

Material of this taxon first came to light in March 2010 ( Feika 78) as a result of a baseline botanical study for the transport corridor for the Tonkolili iron ore mine, at that time operated by African Minerals Limited (AML) but now owned by Shandong Iron & Steel. Feika 78 was found to be a mixed collection of I. ledermannii (formerly Ledermanniella ledermannii ) segregated as Feika 78A, with a second undescribed species (segregated as Feika 78B) which was recognised as new to science and drawn up for publication ( Fig. 2 ). Since the 6 ribbed ovary and fruit (resulting from inverted flowers) was strongly laterally compressed, the generic attribution of Macropodiella Engl. was initially made, following the prevailing classification of Cusset (e.g., Cusset 1987). However, in the interim increasingly better sampled molecular studies ( Moline et al. 2007, Thiv et al. 2009, Schenk et al. 2015) have thrown doubt on some of the generic limits of Cusset’s classification (1978, 1983, 1984, 1987). So far as Macropodiella and Ledermanniella are concerned, morphological data also give cause to doubt the generic delimitation ( Cheek & Ameka 2016). It is now clear that Feika 78B, due to the flattened, sometimes lobed, scale-like scale-leaves that it presents, is unambiguously best placed in the newly resurrected genus Inversodicraea ( Cheek & Haba 2016a) . Since the completion of Fig. 2 , extensive additional material (17 sheets) was collected from the same site in December 2010 ( Feika 146) which shows additional character of the taxon and which has been selected as type of the species and illustrated as Fig. 3 .

Figures

Fig. 2 Inversodicraea feika Cheek. a. Habit in dry season; a1. branched, erect flowering plant, leaves fallen; a2. subcylindrical root developing from old stem; b1. detail of a1; b2. detail of spur shoot with scale-leaves; c. stolon-like root upper surface, showing opposite, distichous short leaves and endogenous branch- ing; d. stolon-like root, lower surface, with two undifferentiated endogenous root branches (detail from a2); e. spur shoot with spathellum just after dehiscence; f. spur shoot, with flower at anthesis; g. fruit; h. fruit in transverse section, three seeds in lateral view above (all from Feika 78B, K). — Scale bars: a = 1 cm; b–d = 5 mm; e–g = 2 mm; h, b (small inset) = 0.5 mm. — Drawn by Andrew Brown.

Fig. 3 Inversodicraea feika Cheek. a. Habit, end wet season,long stem with branches,dichotomous leaves attached; b. detail of spur shoot with scale-leaves, spathellae and one dichotomous leaf; c. flattened, ribbon-like, dichotomous leaf (transverse section at lower right) (all from Feika 146, K). — Scale bars: a = 10 cm; b = 1 cm; c = 2 cm. — Drawn by Andrew Brown.