Ventilago species

Cahen, Daniel & Utteridge, Timothy M. A., 2017, Three new species of Ventilago (Rhamnaceae) from South-East Asia, Phytotaxa 307 (3), pp. 171-182 : 180

Key to Ventilago species of Borneo

1. Fruit wing glabrous.............................................................................................................................................................................2

– Fruit wing hairy..................................................................................................................................................................................3

2. Leaf margin distinctly crenate; secondary veins [4–]5–8 pairs; horizontal tertiary veins spaced from each other on average by ca. 0.3 mm, higher order venation reticulations indistinct; domatia present, tufts of hairs in secondary vein axils. Persistent calyx cuplike, covering about ½ of fruit’s globose part.................................................................................................. Ventilago malaccensis

– Leaf margin subentire; secondary veins 8–11[–13] pairs; horizontal tertiary veins spaced from each other on average by more than 0.5 mm, higher order venation reticulations distinct; domatia absent. Persistent calyx annular, attached at base of fruit’s globose part...................................................................................................................................................................... Ventilago dichotoma

3. Secondary veins 6–8 pairs, abaxially almost flat; petiole 5–13 mm long. Fruit wings yellowish, chartaceous, to ca. 4 cm long ........................................................................................................................................................................... Ventilago borneensis

– Secondary veins 6–10[–12] pairs, abaxially weakly to conspicuously elevated; petiole 0.5–13 mm long. Fruit wings brownish, subcoriaceous, to ca. 7 cm long..........................................................................................................................................................4

4. Dry leaf often rusty brown; base more or less symmetric; abaxial lamina often hairy; primary vein at least abaxially hairy; secondary veins [6–]8–10[–12] pairs, conspicuously elevated abaxially; petiole 3–13 mm long ................................ Ventilago ferruginea

– Dry leaf yellow-green; base slightly asymmetric; abaxial lamina glabrous; primary vein glabrous; secondary veins 6–9[–11] pairs, weakly to moderately elevated abaxially; petiole 0.5–4 mm long .................................................................... Ventilago flavovirens