Contains 59 accepted taxa overall.
Characteristics
Classification
Citation
DICHANTHELIUM (Hitchcock & Chase) Gould, Brittonia 26: 59. 1974.
BASIONYM: Panicum Linnaeus, subg. Dichanthelium Hitchcock & Chase, Contr. U.S. Natl. Herb. 15: 142. 1910.
TYPE: Dichanthelium dichotomum (Linnaeus) Gould (Panicum dichotomum Linnaeus)
Species
Identification Key
1. Plant rather low, with numerous basal spreading or sprawling branches and leaves, the inflorescence often not exceeding or only slightly exceeding the leaves
1. Plant usually elongate and erect, unbranched or some branches cauline, with numerous cauline leaves, the inflorescence exserted or not
2
2. Ligules (or pseudoligule) of hairs 1-5 mm long, at least some hairs 2-5 mm long
2. Ligules (or pseudoligule) membranous or of hairs to 1.8(2) mm long
3
3. Leaf sheaths mottled, sometimes viscid; culm stout 2-6 mm wide
3. Leaf sheaths not mottled (if mottled, culm slender, 0.3-2 mm wide)
4
4. Leaf blades rounded-cordate at the base, the blade base abruptly contracted to the sheath
4. Leaf blades generally cuneate at the base, gradually narrowed to the sheath
5
5. Distal internodes greatly elongated, the leaves nearly all in the basal part, mostly with only a solitary leaf (often reduced in size) somewhat midway between the basal leaves and the inflorescence
5. Distal internodes subequal to proximal ones, the leaves usually well developed throughout the culm below the inflorescence
6
6. Lower glumes thinner and more weakly veined than the upper glumes, attached 0.1-0.5 mm below the upper glumes, the bases clasping the pedicels; spikelets attenuate basally
7
6. Lower glumes similar in texture and vein prominence to the upper glumes, attached immediately below the upper glumes, the bases not clasping the pedicels; spikelets usually not attenuate basally
9
7. Culm leaf blades 2-7 cm long, 7-12 times as long as wide, not or slightly involute, spreading, without raised veins, not longitudinally wrinkled; spikelets obovoid-obpyriform, planoconvex in side view
7. Culm leaf blades 4-16 cm long, 15-50 times as long as wide, or involute, stiffly erect or ascending, with prominently raised veins, the lower blades usually longitudinally wrinkled; spikelets ellipsoid to obovoid, biconvex in side view
8
8. Culm internodes and nodes, and spikelets densely villous or densely pubescent
8. Culm internodes and nodes, and spikelets glabrous to moderately pubescent
9. Culms 5-40(55) cm tall, delicate, 0.2-0.8(1.6) mm wide; spikelets 1.1-1.7 mm long; larger leaf blades 1.5-6 cm long, 1.5-6 mm wide
9. Culms (18)40-100 cm tall, rarely delicate, (0.8)1-2 mm wide; spikelets 1.5-2.7 mm long; larger leaf blades 3.5-14 cm long, 5-14 mm wide
1. (Key A) Leaf sheath hairs retrorse to spreading; distal leaf blades 4-17 cm long, at least 3/4 as long as basal ones, the margins short-ciliate; spikelets with papillose-based hairs
1. Leaf sheath glabrous or hairs ascending; distal leaf blades 1.5-6 cm long, <3/4 as long as basal ones, the margins with papillose-bsed cilia; spikelets glabrous or pubescent, lacking papillae
2
2. Spikelet pubescent, 1.5-2.1 mm long
2. Spikelet glabrous, 1.1-1.8 mm long
3
3. Stem nodes and leaf blade surfaces glabrous
3. Stem nodes and leaf blade surfaces pubescent
1. (Key B) Spikelets 2.5-4.3 mm long, usually obovoid, turgid; upper glumes usually with an orange or purple spot at the base, the veins prominent
2
1. Spikelets 0.8-3 mm long, ellipsoid or obovoid, not turgid; upper glumes lacking an orange or purple spot at the base and the veins not prominent
4
2. Culm nodes with dense, spreading to retrorse hairs; leaf blade lower surface softly velvety pubescent
2. Culm nodes glabrous or sparsely pubescent; eaf blade lower surface glabrous or pubescent, but not velvety pubescent
3
3. Ligule of hairs 2-3 mm; larger leaf blades 4-9 mm wide, 10-15 times longer than wide, often partly involute; Spikelets ellipsoid to oblong-obovoid, (3)3.4-4.2 mm long, 1.7-2(2.2) mm wide, sparsely pubescent or rarely glabrous;
3. Ligule of hairs 1-1.5 mm long; larger leaf blades 6-15 mm wide, 7-10 times longer than wide, flat; spikelets broadly obovoid-ellipsoid, 2.7-3.5 mm long, 2-2.4 mm wide, glabrous or rarely sparsely pubescent
4. Sheaths with hairs to 4 mm long; spikelets 1.8-3 mm long
5
4. Sheaths glabrous or pubescent with hairs no more than 3 mm long; spikelets 0.8-2.1 mm long
7
5. Proximal culm internodes and associated leaf sheaths with soft, spreading or retrorse, papillose-based hairs, the longer hairs to 4-7 mm long; spikelets 1.8-2.5 mm long
5. Proximal culm internodes and associated leaf sheaths glabrate or with ascending or appressed hairs (lacking papillae) 2-4 mm; spikelets 2.1-3 mm long
6
6. Basal leaf blades with long-ciliate on or near the margins and bases; spikelets 2.5-3 mm long
6. Basal leaf blades lacking long cilia on or near the margins and bases; spikelets 2.1-2.6 mm long
7. Culms weak, 0.3-0.8 mm wide; spikelets 0.8-1.1 mm long, puberulent to subglabrous
7. Culms weak to robust, (0.8)1-2.5 mm wide; spikelets 1.1-2.1 mm long
8
8. Spikelets 1.1-1.5 mm long
9
8. Spikelets 1.3-1.6 mm long
10
9. Culm nodes, internodes, and leaf sheaths pubescent to glabrate
9. Culm nodes, internodes, and leaf sheaths glabrous
10. Inflorescence 2-6 times as long as wide, the branches ascending-appressed; spikelets ascending to appressed
10. Inflorescence 1-2 times as long as wide, the branches spreading to ascending; spikelets diverging to ascending
11
11. Culm nodes, internodes, and leaf sheaths glabrous
11. Culm nodes, internodes, and leaf sheaths pubescent to glabrate
12
12. Culms and proximal leaf sheaths with spreading long hairs (sometimes with short hairs also present); leaf blade lower surface softly pubescent
12. Culms and sheaths pilose with with mostly ascending hairs or short spreading hairs; leaf blade lower surface appressed-pubescent or puberulent
1. (Key C) Culms nodes densely villous, often turgid, subtended by a viscid glabrous ring; leaf blades densely soft pubescent
1. Culm nodes glabrous or sparsely pubescent, not turgid; leaf blades glabrous or sparsely pubescent
2
2. Cauline blades 15-30 mm wide, apices flat, acuminate; spikelets sparsely pubescent
2. Cauline blades 7-15 mm wide, apices involute, long tapering; spikelets glabrous or sparsely puberulent
1. (Key D) Culm leaf blades ascending, some margins often with white-cartilaginous; spikelets 1-1.4 mm long
1. Culm leaf blades ascending to spreading. lacking white, cartilaginous margins; spikelets 1.4-5.2 mm long
2
2. Spikelets 1.4-2.2 mm long
2. Spikelets 2.4-3.2 mm long
3
3. Ligule membranous-ciliate, 0.4-0.9 mm long; spikelets 3.8-5.2 mm long; some lower florets staminate
3. Ligule membranous-ciliate, 0.1-0.4 mm long; spikelets 2.2-3.2 mm long; ligules about 0.3 mm long; blades 5-25 mm wide; lower floret sterile
4
4. Leaf blade undersides glaucous, light green
4. Leaf blade undersides green, not glaucous
5
5. Culm leaf blades nearly linear, 5-14 mm wide, 9-12 times as long as wide; spikelets 3-3.2 mm long; spikelets ca. 2 times as long as the lower glume
5. Culm leaf blades ovate-lanceolate, 6-25 mm wide, 4-8 times as long as wide; spikelets 2.6-3.2 mm long; spikelets ca. 4 times as long as the lower glume
6
6. Culms more or less erect, with caudices; leaf blades nearly symmetrical, straight; spikelets 2.6-2.9 mm long; lower lemma apex obtuse
6. Culms decumbent or sprawling, with loose caudices or rhizomes; leaf blades strongly asymmetric-falcate; spikelets 2.9-3.2 mm long; lower lemma apex acute
1. (Key E) Culm leaf blades 2-5 cm long, 2.5-4.5 mm wide; spikelets 1.5-2.0 mm long, puberulent to nearly glabrous
1. Culm leaf blades 4-7 cm long, 3.5-8 mm wide; spikelets 1.8-2.6 mm long, usually densely pubescent or puberulent (rarely glabrous);
2
2. Basal leaf blades 2-5 cm long; culm leaf blades 2-5 mm wide, spreading (patulum)
2. Basal leaf blades 3-8 cm long; culm leaf blades 6-12 mm wide, ascending
1. (Key F) Spikelets 2.9-3.6 mm long, strongly attenuate at the base; lower glumes attached 0.3-0.5 mm below the upper glumes
1. Spikelets 1.7-3(3.2) mm long, not strongly attenuate at the base; lower glumes attached 0.1-0.2 mm below the upper glumes
2
2. Basal leaf blades 1-3 cm long, often <½ as long as the cauline blades; inflorescence usually more than ½ as wide as long, branches spreading; spikelets 1.7-2.3 mm long
2. Basal leaf blades 4-8 cm long, mostly >½ as long as the cauline blades; inflorescence usually less than ½ as wide as long, branches ascending to erect; spikelets (1.8)2-3(3.2) mm long
3
3. Larger cauline blades 5-8 cm long, 3-5 mm wide, 10-25 times as long as wide; inflorescence usually <1/4 as wide as long, branches strongly ascending to erect; spikelets 1.8-2.2 mm long, pubescent, apex obtuse; upper glume and lower lemma reaching the upper lemma
3. Larger cauline blades 5-9 cm long, 2-3 mm wide, 15-40 times as long as wide; inflroescence usually 1/4-1/2 as wide as long, branches ascending; spikelets 2.3-3(3.2) mm long, glabrous to sparsely pubescent, apex acute; upper glume and lower lemma exceeding the upper lemma
4
4. Culms, leaf sheaths, and spikelets usually pubescent, at least proximally
4. Culms, leaf sheaths, and spikelets sparsely pubescent to almost glabrous
1. (Key G) Culm nodes pubescent; leaf sheath with spreading hairs; ligule of hairs 1-2 mm long
1. Culm nodes glabrous to sparsely pubescent; leaf sheath glabrous or sparsely ciliate; ligule of hairs 0.2-1 mm long
2
2. Culms reclining or weakly erect; ligule of hairs (0.2)0.8-1.8 mm long; cauline leaf blade margins not white-cartilaginous
2. Culms erect, sometimes geniculate basally; ligule of hairs 0.2-0.7 mm long; cauline leaf blade margins white- cartilaginous
3
3. Culms and branches few; cauline leaf blades flat, the bases rounded; flag leaves subtending inflorescence much shorter than proximal leaves
3. Culms and branhces numerous; cauline leaf blades often involute, the bases subcordate; flag leaves subtending inflorescence slightly shorter than proximal leaves
4
4. Culms 5-20 cm tall, glabrous or puberulent; spikelets 1.3-1.5 mm long, puberulent
4. Culms 10-45 cm tall, glabrous; spikelets 1.1-1.4 mm long, glabrous
1. (Key H) Proximal nodes pubescent (or culms erect, terete, leaf blades spreading)
2
1. Proximal culm nodes glabrous (culms weak, flattened if leaf blades spreading)
4
2. Spikelets 1.5-1.8 mm long, upper floret 0.6-0.8 mm wide
2. Spikelets 1.8-2.5 mm long; upper floret 0.7-1.0 mm wide
3
3. Culm nodes often glabrous, sometimes pubescent; spikelets glabrous, rarely pubescent; mid-culm leaf blades 5-7 mm wide
3. Culm nodes pubescent; spikelets pubescent; mid-culm blades 7-14 mm wide
4. Culms weak, reclining or sprawling, often flattened; leaf blades spreading, green; inflorescnece branches spreading to ascending
4. Culms robust, erect, terete; leaf blades ascending, green to olive-green; inflorescence branches ascending to subappressed
5
5. Leaf blades thickened, olive green; spikelets moderately pubescent
5. Leaf blades moderately thick, green; spikelets glabrous
6
6. Distal leaf sheaths 2.5-7.5(10.5) mm long; peduncle 5-18.5 cm long; lower glume 0.6-0.9 mm long
6. Distal leaf sheaths (6)8-15 mm long; peduncle (20)30-50(60 cm long; lower glume 0.3-0.7(0.9) mm long
Genus Synonyms
| Synonym | Full Citation | Basionym | Type |
|---|---|---|---|
| No synonyms found. | |||