Crepidorhopalon

Fischer, Eberhard, Darbyshire, Iain & Bingham, Mike G., 2014, A new species of Crepidorhopalon (Linderniaceae) from the Mutinondo Wilderness, Zambia, Phytotaxa 181 (3), pp. 171-178 : 172

Key to the species of Crepidorhopalon with capitate inflorescence

1. Inflorescence surrounded by 2 whorls of large involucral leaves of 15–27 × 10 mm, bracts linear-lanceolate, calyx densely wooly at base ...................................................................................................................................... C. involucratus (Philcox) Eb.Fischer

- Inflorescence different, involucral leaves if present usually only slightly larger than bracts, calyx usually glabrous to sparsely pubes cent, wooly only in C. parviflorus but then involucral leaves lacking ...................................................................................2

2. Outer bracts of inflorescence broadly ovate (-orbicular), width about ¾ of their length or more, distinctly acuminate..................3

- Outer bracts of inflorescence ovate to linear-lanceolate, width not exceeding 2/3–½ of their length ...............................................7

3. Bracts 5 × 2–3 mm ovate-orbicular at base, with long acuminate apex, leaves at base of capitulae lanceolate, with dentate margin, basal leaves linear-lanceolate .................................................................................................. C. chironioides (S.Moore) Eb.Fischer

- Bracts 4–8 × 3–5.5 mm, nearly orbicular, with short pointed apex, leaves at base of capitulae (if present) ovate to linear-lanceolate, with entire to dentate margin, basal leaves lanceolate, ovate or broadly ovate..................................................................................4

4. Calyx glabrous or with minute hairs along the margin only, vegetative parts glabrous.....................................................................5

- Calyx hairy throughout, vegetative parts at least basally pubescent ..................................................................................................6

5. Bracts dentate, leaves orbicular, 14 x 7–8 mm, coarsely dentate, peduncle 8–12 mm long ........................ C. symoensii Eb.Fischer

- Bracts entire, leaves lanceolate or ovate, 9–17 x 4–10 mm, minutely dentate, peduncle 60–105 mm long... C. mutinondoensis sp. nov.

6. Bracts with dentate margin, calyx 5 mm long, densely wooly at base, lobes glabrous, corolla tube 5.5 mm long, lower lip 3–4 mm long.............................................................................................................................................. C. parviflorus (Philcox) Eb.Fischer

- Bracts with entire margin, calyx 7–7.5 mm long, hairy throughout, corolla tube 7–8 mm long, lower lip 5–6 mm long .............. ..................................................................................................................................................... C. latibracteatus (Skan) Eb.Fischer

7. Calyx winged, leaves rosulate, inflorescence on long leafless peduncle ..................................... C. welwitschii (Engler) Eb.Fischer

- Calyx not winged, leaves scattered on stem.......................................................................................................................................8

8. Calyx with distinct tube, divided up to ¼ of its length.......................................................................................................................9

- Calyx divided for more than ½ of its length or to base (sepals free) ...............................................................................................10

9. Plants up to 50 cm tall, leaves ovate-lanceolate, obtuse, corolla tube 6 mm long, lower lip 6 mm long .............. ................................................................................................................................................. C. schweinfurthii (Oliver) Eb.Fischer

- Plants not exceeding 20 cm, leaves ovate-lanceolate, acuminate, corolla tube 4 mm long, lower lip 4 mm long .............................. ............................................................................................................................................................. C. gracilis (Pilger) Eb.Fischer

10. Plants with elongated stems, at least 7 cm (- 28 cm) tall, flowers purple-violet, upper lip of corolla entire, leaves linear-lanceolate ..................................................................................................................................................... C. tenuifolius (Philcox) Eb.Fischer

- Plants with short stems not exceeding 3 cm, giving the plant a rosulate aspect, flowers whitish to yellowish, upper lip of corolla bipartite, leaves ovate-orbicular .......................................................................................................................................................11

11. Calyx subglabrous with few glandular hairs, corolla whitish, tube 3 mm long, lower lip 2 mm long, abaxial stamens 1.5 mm long, style 4 mm long ............................................................................................................................................. C. malaissei Eb.Fischer

- Calyx densely pubescent with multicellular hairs, corolla yellowish, tube 6–6.5 mm long, lower lip 5 mm long, abaxial stamens 4 mm long, style 8 mm long............................................................................................................................... C. robynsii Eb.Fischer