Neoschumannia gishwatiensis Eb. Fischer, Killmann & Meve 2013, sp. nov.
Creators: name: Fischer, Eberhard
name: Killmann, Dorothee
name: Meve, Ulrich
Publisher: name: Zenodo
Year: 2013
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Gentianales
Apocynaceae
Neoschumannia
Neoschumannia gishwatiensis

description: Neoschumannia gishwatiensis Eb.Fischer, Killmann & Meve, sp. nov. (Figs. 1 & 2)
Ab omnibus speciebus Neoschumanniae adhuc cognitis gemmis obovatis, corolla lobis ellipticis, emeraldis, nitidis, corona gynostegiali partibus extendibus basali discoidis conjunctis differt.
Type:— RWANDA. Northern Province: Gishwati Forest Reserve, 29°21’22”E, 1°49’36”S, 2170 m, 2 October 2009, Fischer 13225 (holotype K!; isotype KOBL!).
Lianas, climbing up to 5 m high, with above-ground runners up to 2 m long. Latex colorless, roots fibrous. Stems twining when support available, 4–5 mm diam, green, glabrous. Petiole up to 2.3 cm long, adaxially channelled; blades elliptic, 9–11 × 5–7 cm, herbaceous to subcoriaceous, basally rounded, acuminate at apex, green, concolor (abaxial side of leaf slightly paler than adaxial side), glabrous, base of lamina adaxially with 2 colleters, stipules reduced or minute, 0.8–1 mm long, glands ovoid. Inflorescences extra-axillary, solitary, many-flowered with 1–2 flowers open at time, pseudo-umbellate, with flowers all arising at apex of peduncle, lax; pedunculate, peduncles filiform, ca. 4–5 cm long, 1.5 mm diam., glabrous; rachis persistent, cylindrical, thick, straight, with numerous lanceolate bracts; pedicels filiform, ca. 4 cm long, 1 mm wide, glabrous. Flowers pendulous. Flower buds obovoid. Calyx aposepalous, sepals lanceolate, ca. 6 mm long, acute, glabrous. Corolla rotate, ca. 25 mm long, apopetalous, petals narrowly elliptic, 24–28 × 8–9 mm, slightly twisted at base and suddenly narrowed to ca. 0.7 mm width, subacute, abaxially greenish, tinged reddish to brownish, adaxially emerald-green, smooth, brilliant, with whitish, vibratile, clavate trichomes, ca. 2 mm long, on base of petals, otherwise glabrous; petals usually slightly spreading at anthesis. Gynostegial corona a basally fused ring of staminal and interstaminal parts which is extended basally into a completely fused skirt; skirt discoid, spreading, fleshy, white, glabrous; staminal corona lobes lanceolate, ca. 2 mm long, conniventerect, purple with translucent-white apex, laterally and abaxially with simple, thin, spreading hairs, 0.4–0.5 mm long, translucent-white; interstaminal corona lobes deltoid, ca. 2 mm long, ascending-erect with apex slightly recurved, canaliculate, occasionally apically notched, white with purple dots, laterally and abaxially covered with simple, thin, spreading hairs, 0.5-0.6 mm long, translucent-white. Gynostegium with corona atop a column, exposed above corolla, column cylindrical, ca. 1.4 × 1.6 mm, whitish. Anthers subquadrate, erect, thickened. Pollinia erect, obovoid, ca. 0.4 × 0.3 mm; corpusculum ellipsoid, ca. 0.2 mm long, with inconspicuous, ellipsoid-deltoid basal projections, caudicles linear, ca. 0.1 mm long, straight. Style head umbonate. Mericarps paired, pendulous, narrowly oblong, terete, 26–30 cm long, 4–5 mm diam., acute-angled (20–30°), shortly beaked, mottled whitish green, green or dark green, glabrous. Seeds ovate, 11 × ca. 4 mm, brown, wing ca. 1 mm wide; coma ca. 30 mm long, white.
Habitat:—This species was found near the edge of the Gishwati Forest Reserve, in degraded secondary forest dominated by Neoboutonia macrocalyx Pax, Macaranga kilimandscharica Pax, Polyscias fulva (Hiern) Harms, Carapa grandiflora Sprague, Vernonia auriculifera Hiern, and Solanecio mannii (Hook. f.) C.Jeffrey at 2170 m altitude. The Gishwati Forest is a remnant of a once larger montane forest (Mildbraed 1914) that was mostly destroyed in the 1980’s due to a World Bank project, and converted into pastures. The remaining forest relic was again logged after 1994. However, it still harbors a unique diversity and species new to science were recently discovered (Fischer et al. in prep.). The local fauna is also very rich, and a small population of chimpanzees is still present (R. Chancelor & A. Rundus, pers. comm.). For a description of the vegetation of the Gishwati Forest, see Fischer & Hinkel (1994).
Conservation Status: — Neoschumannia gishwatiensis is only known from the type locality in the Gishwati Forest Reserve. According to the IUCN criteria (IUCN 2012) it can be assessed as critically endangered (CR). However, the species may be more widespread in similar forests of Rwanda (e.g., Nyungwe National Park; Fischer & Killmann 2008), Burundi (Kibira National Park) or the Democratic Republic of Congo (Kahuzi-Biéga National Park; Fischer 1996). It may be overlooked as it is not very conspicuous without flowers and fruits and resembles other apocynaceous lianas. Rwanda has a special responsibility for the conservation of this unique species.
description: Published as part of Fischer, Eberhard, Killmann, Dorothee & Meve, Ulrich, 2013, Neoschumannia gishwatiensis (Apocynaceae, Asclepiadoideae-Ceropegieae) from Gishwati Forest, Rwanda-a third and new species from a disjunct African genus, pp. 19-26 in Phytotaxa 77 (2) on pages 20-23, DOI: 10.11646/phytotaxa.77.2.1, http://zenodo.org/record/5066791