Eupatorieae

Grossi, Mariana A., Katinas, Liliana & Nakajima, Jimi N., 2013, Criscianthus, a new genus of Eupatorieae (Asteraceae) with a key to members of the tribe in Africa, Phytotaxa 141 (1), pp. 25-39 : 32-33

Key to the species of Eupatorieae in Africa

1. Pappus capillary........................................................................................................................................................... 2.

– Pappus not capillary................................................................................................................................................... 22.

2. Mostly scandent vines or leaning on vegetation.......................................................................................................... 3.

– Herbs or shrubs erect, not scandent ........................................................................................................................... 13.

3. Phyllaries and florets in number of four ...................................................................................................................... 4.

– Phyllaries and florets more than four ........................................................................................... Chromolaena odorata

4. Leaves palmately cleft into 3–7 irregularly toothed to entire lobes. Pappus bristles ca. 1 mm long .... Mikania carteri

– Leaves with entire, serrate, or dentate margins. Pappus bristles 3 mm long or more ................................................. 5.

5. Stems hexagonal, the angles with narrow wings. Corolla teeth ca. three times the length of the throat ....................... ........................................................................................................................................................ Mikania microptera

– Stems terete or nearly so, after drying multi-striate to costulate, not winged. Corolla teeth shorter than or of the same length as the throat ....................................................................................................................................................... 6.

6. Synflorescence a lax cymose panicle; pedicels 5–15 mm long. Corolla tube two times the length of the throat or longer ..................................................................................................................................................... Mikania chevalieri

– Synflorescence an open to dense corymb or a corymbose panicle; pedicels up to 5 mm long; corolla tube approx. of the same length as the throat ........................................................................................................................................ 7.

7. Leaves cordate, lanceolate, or triangular .................................................................................................................... 8.

– Leaves ovate .............................................................................................................................................................. 12.

8. Leaves cordate ............................................................................................................................................................. 9.

– Leaves lanceolate or triangular ................................................................................................................................. 11.

9. Heads 4–7 mm long ................................................................................................................................................... 10.

– Heads 7–7.5 mm long .......................................................................................................................... Mikania cordata

10. Phyllaries linear-oblong ..................................................................................................................... Mikania scandens

– Phyllaries ovate-oblong or elliptic.................................................................................................. Mikania micrantha

11. Leaves lanceolate, 2 times or more longer than wide..................................................................... Mikania sagittifera

– Leaves triangular, ca. one and one-half times longer than wide ...................................................... Mikania natalensis

12. Heads 9–12 mm long; capitulescence a dense corymb...................................................................... Mikania capensis

– Heads 4–7.5 mm long; capitulescence a rather open corymb or a corymbose panicle .......... Mikania chenopodiifolia

13. Leaves at the median part of the stem alternate or opposite, never verticillate......................................................... 14.

– Leaves at the median part of the stem verticillate ................................................................... Criscianthus zambiensis

14. Receptacle rounded to conical, with scars ................................................................. Campuloclinium macrocephalum

– Receptacle flat, completely naked ............................................................................................................................. 15.

15. Florets 10–60 ............................................................................................................................................................. 16.

– Florets 4–8 ................................................................................................................................................................ 19.

16. Phyllaries equal in length; inner phyllaries acute at the apex. Cypselae with inconspicuous basal callus or carpopodium .............................................................................................................................................................. 17.

– Phyllaries unequal, the outher shorter; inner phyllaries aristate at the apex. Cypselae with a well delimited and conspicuous basal callus or carpopodium ................................................................................ Fleischmannia microstemon

17. Leaves ovate-deltoid, cordate or cordate-ovate ......................................................................................................... 18.

– Leaves elliptic ..................................................................................................................................... Ageratina riparia

18. Capitula peduncles densely stipitate-glandular.......................................................................... Ageratina adenophora

– Capitula peduncles puberulent (not glandular) or glabrous ............................................................. Ageratina altissima

19. Stems hollow and fistulose. Leaves pinnately veined. Cypselae with a papillose aspect, mostly with glandular hairs and few or absent non-glandular (twin) hairs ......................................................................... Eupatorium cannabinum

– Stems not fistulose. Leaves triveined. Cypselae with a hispid aspect, mostly with non-glandular (twin) hairs and few glandular hairs............................................................................................................................................................ 20.

20. Leaves 3.5–7 cm wide, cordate at the base. Anthers with apical appendage truncate and emarginate at the apex........ ....................................................................................................................................................... Stomatanthes meyeri

– Leaves 0.2–2.2 cm wide, cuneate or rounded at the base. Anthers with apical appendage rounded at the apex ...... 21.

21. Leaves ovate, pubescent below. Phyllaries pubescent ............................................................... Stomatanthes africanus

– Leaves oblong-lanceolate to linear, glabrous below. Phyllaries glabrous ................................... Stomatanthes helenae

22. Pappus of 3–5 elongate, viscid-tipped knobs............................................................................................................. 23.

– Pappus coroniform, of 5–6 short (up to 3 mm) free scales, rarely with setae or absent............................................ 26.

23. Stems decumbent. Cypselae surface not spiny ................................................................... Adenostemma mauritianum

– Stems erect. Cypselae muricate, covered with many short spines............................................................................ 24.

24. Aquatic plants; stems fleshy ...................................................................................................... Adenostemma caffrum

– Terrestrial plants; stems not fleshy ............................................................................................................................ 25.

25. Leaves oblong-elliptic, base attenuate. Corolla white ............................................................. Adenostemma schimperi

– Leaves ovate, base rounded-cuneate. Corolla white or violet .................................................. Adenostemma viscosum

26. Phyllaries glabrous or sparsely pilose, margins often ciliate ........................................................ Ageratum conyzoides

– Phyllaries with numerous sticky hairs, margins not ciliate or inconspicuously ciliate .......... Ageratum houstonianum