Adenia angulosa G.W.Hu & Q.F.Wang, 2017

Ngumbau, Veronicah Mutele, Nyange, Mwadime, Dai, Can, Zhong, Zhi-Xiang, Wei, Neng, Malombe, Itambo, Hu, Guang-Wan & Wang, Qing-Feng, 2017, Adenia angulosa (Passifloraceae), a new species from coastal forests of Kenya and Tanzania, Phytotaxa 313 (1), pp. 137-142 : 138-141

Adenia angulosa G.W.Hu & Q.F.Wang , sp. nov. ( Fig. 1 : A–I; Fig. 2 : A, C, E, G, I, K, M, O)

Diagnosis: —The new species resembles A. gummifera , but differs by its 3–5-angled older stems, deeply (3–)5(–7)-lobed leaves in juvenile plants and juvenile branches, 3(–4)-flowered male and 1–2(–3)-flowered female inflorescences, filaments connate for more than half of their length and fruits 1–2(–3) per infructescence, narrowly ovoid, 6-angled.

Type: — KENYA, Coast Province: Kwale District, Shimba Hills National Reserve, Mwele Forest , elev. 330 m, 27 September 2016, SAJIT 06061 (Male) (holotype HIB!; isotype EA!, HIB!) .

Large dioecious liana, to 20 m long, to 60 mm in diam.; older stem 3–5-angled, twigs terete, grey-green, pruinose. Leaf blades on juvenile plants and branches deeply (3–)5(–7)-lobed with pentagonal outline, lobes up to 40 mm, pinnatilobate to pinnatipartite with 1–3 pairs of smaller lobes; leaf blades on mature branches entire or shallowly 3(–5)-lobed with reniform to subrotund outline; blade size 10–90 × 8–70 mm; 3-nerved at or very near base, another pair of straight nerves from the lower-middle part of midrib, reticulation fine, distinct; margin entire; leaf base truncate to shallowly cordate, apex round or slightly concave; petiole 10–80 mm. Blade-base gland single, subsemicircular, blade gland 0–5, marginal glands 1–3 on either side of the blade. Stipule reniform to broadly rounded, margin finely erose, ca. 1 mm. Inflorescences pedunculate for (3–)10–70(–100) mm, (1–)2–3(–4) flowers in males, 1–2(–3) flowers in females, the end reduced into tendril, tendril simple, 7–30 mm, sometimes absent or caducous; sterile tendrils simple to trifid, 45–110 mm. Male flowers not opening widely, tubiform-campanulate, 13–18 × 4–6 mm, including 3–6 mm long stipe, hypanthium cup-shaped, 1–2 × 4 mm; sepals 5, narrowly elliptic, 9–11 × 2–3 mm, margin entire or only distal third erose; petals 5, oblanceolate, 10–12 × 2–3 mm, distal half of margin finely erose, basal half nearly entire; stamens 5, filaments 2.0– 2.5 mm, connate for half their length or more, inserted at the base of hypanthium, anthers 4–5 mm, obtuse, linear; septa 0; corona 0; disk gland 0; pistillode ca. 1 mm, enclosed in the filament tube. Female flowers campanulate, opening more widely than male ones, 5–10 mm including ca. 1 mm long stipe; hypanthium shallowly cup-shaped, ca. 1 mm; sepals 5, narrowly elliptic, 6–8 × 1.5–2.5 mm, margin entire; petals 5, oblanceolate-linear, obtuse, 3–7 × 1 mm, margin erose at tip; staminodes 5, ca. 0.5 mm; septa 0; corona 0; disk glands 0; gynophore ca. 0.5 mm, ovary ovate, 6 angular, 6–8 mm, style ca. 0.5 mm, stigmas 3, subsessile, reniform, laciniate papillate, and each ca. 1 mm in diameter. Fruits 1–2(–3) per infructescence, narrowly ovoid, 6 angular, 36 × 15 mm excluding ca. 1 mm long gynophore. Pericarp woody-coriaceous, ca. 0.5 mm thick, finely granulate to nearly smooth. Seeds 45–50 per capsule, ovoid, 3.6–3.8 × 2.8–3.0 mm, testa pitted.

Distribution and ecology: —This new species has only been found in coastal forests of Shimba Hills National Reserve in Kenya and Lushoto in Tanzania. In Kenya, it is locally common at Shimba Hills. The species occurs in moist forest, along road sides and forest margins accompanied by Paramacrolobium Léonard (1954: 348) , Parkia filicoidea Oliver (1871: 324) , Keetia venosa ( Oliver (1873: 85)) Bridson (1986: 974), Catunaregam spinosa ( Thunberg (1780: 16)) Tirvengadum (1978: 13), etc.

Phenology:—The new species was found in flower from April to October and with fruits from June to December.

Etymology:—The species epithet ‘ angulosa’ refers to the angled character of its older stems and fruits.

Other specimens examined (paratypes): — KENYA, Coast Province, Kwale District, Shimba Hills National Reserve: Mwele , 300 m, 16 October 1991, Luke 2920 (Male) ( EA!) ; 240 m, 14 June 2016, Veronicah & Mwadime SAJIT-V-0171a (Male), Veronicah & Mwadime SAJIT-V-0171b (Female); Shedrick fall, 140 m, 23 September 2016, SAJIT 005956 (Female) ( EA!, HIB!) ; Kivumoni Area , 330 m, 24 September 2016, SAJIT 005975 (Male) ( EA!, HIB!) ; 310 m, 24 September 2016, SAJIT 005981 (Female) ( EA!, HIB!) ; Mwele area , 340 m, 28 September 2016, SAJIT 006074 (Female) ( EA!, HIB!) . TANZANIA: Lushoto, Kwamkoro–Sangerawe , 27 December 1946?, Zimmermman G. 6574 (Male) ( EA!) .

Affinities:— Adenia angulosa has the characters, including leaf base with single gland, variation in leaf shape, leaf venation, flowers lacking disk glands, sepals free or fused at the very base, stigmas sub-sessile, all of which group it into A. sect. Ophiocaulon ( Hooker (1867: 813)) Harms (1897: 255) ( De Wilde 1968). Further, in the classification of A. sect. Ophiocaulon , De Wilde (1968) divided the species into different groups. In this section, A. angulosa is similar to A. gummifera , A. cissampeloides (Planchon ex Hooker (1849: 365)) Harms (1897: 225) and A. stolzii Harms (1912: 35) , but can be distinguished by its 3–5-angled older stems, deeply 5-lobed leaves in juvenile plants and branches, 2–3-flowered male inflorescence, 1–2-flowered female inflorescence, sepals not punctate, filaments connate for more than half their length, fruit 1–2(–3) per infructescence, narrowly ovoid, 6-angled, seeds ovate, 3.6–3.8 × 2.8–3.0 mm ( Table 1 & Figure 2 ).

stolzii .

Figures

FIGURE 1. Adenia angulosa: morphology.A. Branch with male flowers. B. Old stem. C. Lobed leaf of juvenile branch (showing gland). D. Reniform leaf of mature plant. E. Male flower. F & G. Female flower. H. Fruit. I. Inside of fruit. Scale bars: B, C, D, H, I = 10 mm; E, F, G = 2 mm.

FIGURE 2. Comparison of Adenia angulosa and A. gummifera. A. Juvenile plant of A. angulosa. B. Juvenile plant of A. gummifera. C. Cross section of old stem of A. angulosa. D. Cross section of old stem of A. gummifera. E. Leaf from mature branch of A. angulosa. F. Leaf from mature branch of A. gummifera. G. Male inflorescence of A. angulosa. H. Male inflorescence of A. gummifera. I. Male flower of A. angulosa. J. Male flower of A. gummifera. K. Female flower of A. angulosa with ovate ovary. L. Female flower of A. gummifera with ellipsoid ovary. M. Fruits of A. angulosa. N. Fruits of A. gummifera. O. Seeds of A. angulosa. P. Seeds of A. gummifera. Scale bars:A, B, C, D, E, F, G, H = 10 mm; I, J, K, L = 2 mm.