Zehneria longiflora G.W.Hu & Q.F.Wang, 2017

Wei, Neng, Miyawa, Daniel Odhiambo, David, Melly Kimutai, Ngumbau, Veronicah Mutele, Zhong, Zhi-Xiang, Mwachala, Geoffrey, Hu, Guang-Wan & Wang, Qing-Feng, 2017, Zehneria longiflora (Cucurbitaceae), a new species from Kenya, Phytotaxa 324 (1), pp. 89-94 : 89-92

Zehneria longiflora G.W.Hu & Q.F.Wang , sp. nov. ( Fig. 1 & 2 )

Diagnosis:— Zehneria longiflora is most similar to Z. oligosperma , but differs by its 6.0– 7.5 mm long receptacle-tube, stamens that are inserted in the middle of the receptacle-tube, the up to 3.5 mm long filaments, subumbelliform or racemiform 8- to 30-flowered male inflorescence that is sessile or with a 2–15 mm long peduncule, and the sessile umbelliform female inflorescence.

Type:— KENYA. Nandi County, South Nandi Forest, Kobujoi area , elev. 1970 m, 11 December 2016, Sino-Africa Joint Investigation Team ( SAJIT) 006679 (Female) (holotype HIB!; isotype EA!, HIB!)

Herbaceous climber, 5 m or longer; roots slender, branched, up to 0.5 m long; stem grooved, usually contorted, mostly glabrous except hairy at the nodes. Leaves simple, blade ovate-cordate, hastate to palmately lobed, 40–75 × 30–65 mm; petioles subglabrous, grooved adaxially, usually contorted, up to 60 mm long; blades slightly fleshy, especially in young leaves, subglabrous, scabrid-punctate above, with 1–12 or more deep green glands mainly on the upper (apical) half of leaves, main nerves with sparsely scattered bristles on adaxial surface, glabrous abaxially; margin slightly sinuate-toothed or almost entire; base cordate to truncate, apex acuminate and apiculate; tendrils simple, up to 150 mm long. Dioecious. Inflorescence base with a linear probract, hooked or curly, less than 10 mm long. Male inflorescences axillary, sessile or pedunculate with 2–15 mm long peduncles, subumbelliform or racemiform, 8- to 30-flowered, pedicels 4–20 mm long; receptacle-tube campanulate, 6.0– 7.5 mm long, inner surface of apical half densely hairy, basal part below stamens sparsely hairy, outside surface glabrous; sepal lobes dentiform, ca. 1 mm long; petal lobes ovate, 2.0–3.0 × 1.0– 1.8 mm, reflexed, white, turning cream to yellow when old; stamens 3, inserted in the middle of the receptacle-tube; filaments distinct, ca. 3.5 mm long, glabrous, curved at apex; anthers ellipsoid, ca. 1 mm long, 2-thecous; thecae vertical, slightly curved, 1 mm long, connective elliptic, with finely papillose hairs; disk elevated, free from tube, depressed globose, ca. 1 mm in diam. Female inflorescences axillary, sessile, 5- to 12-flowered or more in umbelliform clusters; pedicel 8–25 mm long; perianth similar to male flowers; ovary subglobose, glabrous, with vertical green stripes; neck dominant, 0.5–3.5 mm long; style 6–7 mm long, glabrous, stigma ca. 2 mm in diam., with 3 down-curved papillose lobes; staminodes 3, inserted 1/4 to 1/3 from the base of the receptacle-tube, linear, glabrous, ca. 4 mm long; disk annular, 3-lobed, surrounding the base of style, free from tube, ca. 0.5 mm high. Fruits clustered, globose, 9–11 mm in diam., subglabrous, densely covered with tiny protuberances. Seed ovate in outline, narrowly bordered, lenticular, compressed, ca. 6 × 4 × 1 mm.

Distribution and ecology:— Four populations of this new species have been found at Kobujoi area in South Nandi Forest of Kenya. Nandi Forest (South and North Nandi Forest) and Kakamega Forest were connected to each other, forming one big “U” shaped forest block at the beginnings of the 1900s ( Schaab et al. 2010). However, the U-shape forest was fragmented and divided into three parts, owing to human pressures. It is possible that Z. longiflora occurs in adjacent areas (like North Nandi Forest and Kakamega Forest) that have not yet been fully explored. It usually climbs on tree trunks or twines around branches of shrubs in moist and shady forest at elevations of 1900–2000 m.

Conservation status:— This new species was only found at Kobujoi area of Nandi Forest. Since there is not enough data on population size and dynamics, an assessment of the current conservation status of this species cannot be given. Therefore, we suggest to evaluate the species as Data Deficient (DD) according to the IUCN Red List Categories and Criteria ( IUCN 2001).

Phenology:— The new species was found with flowers from June to July and November to December. This corresponds to wet seasons of the bimodal rainfall pattern of this region.

Etymology:— The epithet “ longiflora ” refers to the fairly long receptacle-tube of this new species.

Additional specimens examined (Paratypes):— KENYA. Nandi County, South Nandi Forest, Kobujoi area , elev. 1970 m, 11 December 2016, SAJIT 006669 (Male) ( EA! HIB!) & SAJIT 006672 (Male) ( EA! HIB!) ; elev. 1921 m, 1 July 2017, KM 0093 (Male) ( EA! HIB!) ; elev. 1991 m, 2 July 2017, KM 0115 (Female) ( EA! HIB!) ; elev. 1974 m, 2 July 2017, KM 0119 (Male) ( EA! HIB!) .

Specimens examined for Zehneria oligosperma : — TANZANIA. Lushoto District, Lushoto-Mombo Road, 1 mile NE of Vunga turn off, W Usambaras, 1000 m, 14 June 1953, R. B. Drummond & J. H. Hemsley 2915 (isotype EA!) ; Saa Name Island , Mwanza District, Mwanza Region, 17 January 1965, unknown collector 1173 ( EA!) ; Near Songe, 15 miles S of Kijungu , 1500–1800 m, A. S. Vincent 255 ( EA!) ; Lake Daluti, old crater Lake, few miles W of Tengeru and ca. 15 km E of Arusha, F. M. van der Laan 1153 ( EA!) ; Lushoto District, Forest bordering Kumba swamp about 3 miles S of Mashewa , 375 m, 29 June 1953, R. B. Drummond & J. H. Hemsley 3080 ( EA!) ; Konda District, Great North Road, Kolo, 15 miles N of Konda, 1524 m, 12 January 1962, R. Polhill & S. Paulo 1148 ( EA!) ; Ndundulu Forest Reserve , 1440 m, 6 September 2004, W. R. Q. Luke, T. Butynski, C. Ehardt & T. Jones 10370 ( EA!) . KENYA. Ngaia Forest , 1320 m, 13 February 2007, W. R. Q. & P. A. Luke, S. & T. Spawls 11710 ( EA!) ; Nyambeni Hills, Nyambeni Forest Reserve , 2350 m, 25 May 2004, W. R. Q. Luke, R. Copeland & R. Wharton 10280 A ( EA!) ; Chyulu Hills , 2120 m, 21 March 2004, W. R. Q. & P. A. Luke, T. & S. Pocks, & B. Finch 10253 ( EA!) ; Mana-Sand Rwen Confl. , 1524 m, 27 February 1972, S. Taiti ( EA!) .

Figures

FIGURE 1. Line drawing of Zehneria longiflora. A. Branch of male plant. B. Branch of female plant. C. Roots. D. Staminate flower. E. Pistillate flower. F. Fruit. G. Seed. H. Nerves on basal part of adaxial leaf surface (showing sparsely scattered puberulous hairs on middle vein).

FIGURE 2. Photographs of Zehneria longiflora. A. Male plant in the wild. B. Female plant. C. Roots. D. Male inflorescence. E–G. Male flowers. H. Adaxial view of leaves. I. Abaxial view of leaves (showing position of glands). J. Female inflorescence (showing probract). K–O. Female flowers. P. Fruit. Q. Seed. Scale bars: H, I = 5 cm; E, G, M, N, P = 5 mm; F, L, O = 1 mm.