Dichanthelium, (Lam.) Gould (Lam.) Gould

L. Salariato, Diego & O. Zuloaga, Fernando, 2011, New Species of Paniceae (Poaceae, Panicoideae) from Brazil, Systematic Botany (Basel, Switzerland) 36 (1), pp. 53-58 : 54-55

KEY TO D. BARBADENSE AND RELATED SPECIES

The following key provides a delimitation of D. barbadense from species of the genus with a similar geographic distribution.

1. Blades clasping the culm, cordate, width length to width ratio of 3–5(–7):1.............................................................. 2

2. Upper glume and lower lemma 5(–7)-nerved, the nerves inconspicuous, lower lemma inflated at base; upper anthecium inserted laterally in relation to the axis of the rachilla............................................ Dichanthelium sciurotis (Trin.) Davidse

2. Upper glume and lower lemma 7–9-nerved, with prominent nerves; lower lemma not inflated at base; upper anthecium inserted horizontally in relation to the axis of the rachilla............................................................................................. 3

3. Inflorescences 1–2.5(–3) cm long, few–flowered; blades overlapping, 1–3 cm long, 0.3–0.6 cm wide.................................................................. Dichanthelium cumbucana (Renvoize) Zuloaga

3. Inflorescence 2.5–15 cm long, multiflowered; blades not overlapping, 2–12 cm long, 0.5–2 cm wide.................................. 4

4. Spikelets 1.5–2.5 mm long, without a manifest stipe between the lower and upper glume....................................... 5

5. Spikelets short-hispid, 1.5–1.9 mm long; inflorescences 2.5–9 cm long; main axis of the inflorescence densely hirsute; blades ovate-lanceolate, with base asymmetrical.................... Dichanthelium sciurotoides (Zuloaga & Morrone) Davidse

5. Spikelets glabrous, 1.7–2.5 mm long; inflorescences 10–15 cm long; main axis glabrous; blades linear-lanceolate, with base symmetrical................................................... Dichanthelium aequivaginatum (Swallen) Zuloaga

4. Spikelets 2.2–3.3 mm long, with a stipe between the lower and upper glume.................................................. 6

6. Blades with margins cartilaginous and covered with manifest cilia; lower glume ½ or less the spikelet; blades with base symmetrical............................................... Dichanthelium stipiflorum (Renvoize) Zuloaga

6. Blades without cartilaginous margins and without cilia on the upper portions of the margins; lower glume 1/2–3/4 the length of spikelet; blades with base asymmetrical......................................... Dichanthelium pycnoclados (Tutin) Davidse

1. Blade not clasping the culm, narrow to subcordate, width length to width ratio of 10–30:1................................................. 7

7. Lower glume ¼–1/2 the length of the spikelet.................................................................................... 8

8. Plants with prominent glands on sheaths, blades and axis of the panicles........ Dichanthelium adenorhachis (Zuloaga & Morrone) Zuloaga

8. Plants without prominent glands on sheaths, blades and axis of the panicles, occasionally present on the axis of the panicle............ 9

9. Blades 3.5–12(–16) cm long. 0.2–1.3(–1.5) cm wide; panicles 10–15 cm long........... Dichanthelium aequivaginatum (Swallen) Zuloaga

9. Blades 1–3(–6) cm long, 0.2–0.5 cm wide; panicles 3–5 cm long............................................................. 10

10. Spikelets 2–2.3 mm long, ellipsoid, hirsute, covered with whitish hairs; blades linear-lanceolate............................................ Dichanthelium cabrerae (Zuloaga & Morrone) Zuloaga

10. Spikelets 2.5–3.2 mm long, long-ellipsoid, glabrous to sparsely pilose, blades ovate-lanceolate to lanceolate............................... Dichanthelium barbadense Salariato, Morrone & Zuloaga

7. Lower glume ¾–4/5 the length of the spikelet................................................................................... 11

11. Spikelets with a stipe between the lower and upper glume.............................. Dichanthelium congestum (Renvoize) Zuloaga

11. Spikelets without a stipe between the lower and upper glume........................... Dichanthelium assurgens (Renvoize) Zuloaga