Grangea

Beentje, Henk & Lachenaud, Olivier, 2020, The inclusion of Akeassia in Grangea (Asteraceae) and description of a new species from Gabon: Grangea ogoouensis, Candollea 75 (2), pp. 311-319 : 313

Key to the species of Grangea

(Species occurring in Gabon are in bold).

1. Pappus a coroniform ring with dentate or laciniate margin (the ring sometimes very short in G. ceruanoides but then outer florets in a single series) ....................................... 2

1a. Pappus of free bristles, or bristle-scales briefly connate at base, or absent; outer florets in several series ................. 6

2. Leaves shallowly dentate (teeth to 2 mm deep), long-attenuate at base; achenes glandular, without hairs; endemic to Burundi....................................................... G. jeffreyana

2a. Leaves pinnatifid, or if shortly toothed then auriculate at base; achenes mostly hairy (sometimes glabrous in G. maderaspatana ) and often glandular as well .............. 3

3. Capitula 3 – 6 together in terminal corymbs; hairs on achenes simple and uncinate at apex; pappus margin very shortly and irregularly toothed; erect herb; Angola, Zambia, Zimbabwe, Namibia, Botswana................ G. anthemoides

3a. Capitula, at least the majority of them, solitary; hairs on achenes (when present) either bifid, or if simple then not uncinate; pappus margin laciniate with ± linear teeth; erect or decumbent herbs ....................................................... 4

4. Outer florets in one series; achenes eglandular, compressed; Sahelian region from Senegal to South Sudan................. ................................................................... G. ceruanoides

4a. Outer florets in several series; achenes glandular, compressed or quadrangular ................................................ 5

5. Achenes strongly quadrangular in cross section; pappus ring less than 0.5 mm high; phyllaries 2–3 mm long; plant low and very compact, c. 10 cm tall; endemic to Zambia......... ................................................................... G. zambesiaca

5a. Achenes compressed, elliptic and weakly 2(– 4)angled in cross-section; pappus ring to 1.3 mm high; phyllaries 3–7 mm long; plant very variable in habit, usually taller; widespread in tropical and subtropical Africa, Madagascar, and tropical Asia ................................ G. maderaspatana

6. Marginal florets almost urceolate, often red; phyllaries to 4 mm; achenes without hairs; pappus absent or consisting of 1–2 free bristles; Madagascar........................ G. lyrata

6a. Marginal florets with narrow cylindric base, always yellow; phyllaries to 3 mm long; achenes with hairs; pappus present (sometimes caducous in G. gossypina ) ............................ 7

7. Pappus of relatively broad bristle-scales to 1 mm long, shortly connate at base; leaves shallowly dentate; Madagascar............................................... G. madagascariensis

7a. Pappus of smaller and filiform free bristles; leaves shallowly dentate to pinnatifid ...................................................... 8

8. Capitula solitary, on peduncles 1–3 cm long; hairs on achenes uncinate with bifid tips; creeping herb; Madagascar.......... ...................................................................... G. gossypina

8a. Capitula (at least the majority of them) in groups of 2–8, on short peduncles <5 mm long; hairs on achenes simple, not uncinate; erect or clambering herbs ........................ 9

9. Leaves all shallowly dentate with teeth to 3 mm deep; phyllaries 1.2–1.5(–2) × 0.3– 0.4 mm; pappus bristles of outer florets in number 0–3(–5), of inner florets 4–9(–12); widespread in West and Central Africa ... G. grangeoides

9a. Leaves, at least the lower ones, deeply pinnatilobed to pinnatifid; phyllaries 1.2 –2.5 × 0.5–1.2 mm; pappus bristles of outer florets in number 6– 16, of inner florets 12–18; endemic to west-central Gabon................. G. ogoouensis