Thursday, October 29, 2020

[Botany • 2020] Zehneria grandibracteata (Cucurbitaceae ) • An overlooked New Species from western Kenyan Forests


Zehneria grandibracteata G.W. Hu, Neng Wei & Q.F. Wang

in Wei, Zhong, Melly, Kipkoech, ... et Wang, 2020. 

Abstract
Zehneria grandibracteata, a new species of Cucurbitaceae from western Kenya, is described here, based on morphological and molecular data. It has long been misidentified as the widely-distributed species Z. scabra. However, it differs by its ovate leafy probract at the base of the inflorescences, subglabrous condition of the entire plant, shorter receptacle-tube and filaments, as well as denser and sessile inflorescences. Furthermore, the molecular phylogenetic analysis of Zehneria, based on nrITS sequences, further supports the argument that Z. grandibracteata should be segregated from Z. scabra.

Keywords: East Africa, Flora of Kenya, phylogeny, taxonomy, Zehneria scabra

Figure 3. Photographs showing vegetative characters of Zehneria grandibracteata
A climbing stem of female plant in habitat B adaxial lamina C creeping stem D abaxial lamina E probracts at different developing stages F tendril and probract at base of female inflorescence.
 Scale in picture E represents cm.


Figure 4. Photographs showing reproductive characters of Zehneria grandibracteata
A male inflorescence B male flower, side view C male flower, top view D dissected male flower showing disc and stamens
 E female inflorescence F female flower, side view G female flower, top view H dissected female flower showing staminodes 
I pistil and disc J infructescence K cross-section of fruit.
Scale bars: 2 mm (B–D, F–I); 1 cm (J, K).


Zehneria grandibracteata G.W. Hu, Neng Wei & Q.F. Wang, sp. nov.
 
Diagnosis: It is close to Z. scabra, but differs by its consistently ovate leafy probracts (linear minute or even absent in Z. scabra), subglabrous condition of the entire plant (puberulous in Z. scabra), shorter receptacle-tube (1.8–3 mm long vs. 2–5.5 mm in Z. scabra) and filaments (ca. 1.5 mm long vs. 1–2.5 mm in Z. scabra), as well as sessile and denser inflorescences (cluster of 8–30 in male, 6–22 in female vs. 2–60 in male, 1–16 in female in Z. scabra) (Table 2).

Distribution and ecology: Numerous populations of this new species have been documented in the western parts of Kenya’s forests, including Morongiot and Kobujoi areas of South Nandi Forest, Kapsasur area of Nandi Centre, Yale River Trail of Kakamega Forest, Timbilil and Sambret Catchment area of south-western Mau Forest. It usually climbs over tree trunks or twines around shrubs in moist forests or at forest margin at elevations of 1950–2230 m.
 
Etymology: The epithet “grandibracteata” refers to the fairly large leafy probract of this new species.


 Neng Wei, Zhi-Xiang Zhong, David Kimutai Melly, Solomon Kipkoech, Benjamin Muema Watuma, Veronicah Mutele Ngumbau, Peris Kamau, Guang-Wan Hu and Qing-Feng Wang. 2020. Zehneria grandibracteata (Cucurbitaceae), An overlooked New Species from western Kenyan Forests. PhytoKeys. 165: 85-98. DOI: 10.3897/phytokeys.165.57399