Chrysopogon Trinius 1820
Creators: name: Tiwari, Arjun Prasad
name: Landge, Shahid Nawaz
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Liliopsida
Poales
Poaceae
Chrysopogon

description: Key to the species of Chrysopogon in India
1. Racemes short, reduced to a triad of 1 sessile and 2 pedicelled spikelets (rarely with 1–4 spikelet pairs in C. gryllus); lower glume smooth, not tuberculated ....................................................................................................................................................................2
1. Racemes long, multi-spiculated; lower glume tuberculated (Vetiveria group) ................................................................................22
2. Pedicels half as long as the sessile spikelets or longer.......................................................................................................................3
2. Pedicels shorter than half as long as the sessile spikelets ................................................................................................................15
3. Pedicels of the pedicelled spikelets glabrous or nearly so .................................................................................................................4
3. Pedicels of the pedicelled spikelets villous with rusty or pale hairs ..................................................................................................7
4. Culms creeping at the base; sessile spikelets 3.5–4.5 mm long; callus 3.0–6.0 mm long, decurrent, needle like......... C. aciculatus
4. Culms erect; sessile spikelets 5.0– 10 mm long; callus less than 2.5 mm long, not decurrent or needle like ....................................5
5. Panicle lax, bearing a few racemes; sessile spikelets 8.0– 10 mm long; geniculate awn 6.0–7.0 cm long ..................... C. castaneus
5. Panicle contracted, bearing several racemes; sessile spikelets 5.0–8.0 mm long; geniculate awn 2.5–5.0 cm long .........................6
6. Culms robust, more than 95 cm high; leaves sparsely pilose on ad-axial surface; lower glume of sessile spikelets with a row of black spicules on each side of the midrib; upper glume witharista ca. 6.5 mm long........................................................... C. gryllus
6. Culms slender, less than 95 cm high; leaves glabrous; lower glume of sessile spikelets minutely scaberulous-spinulose towards the truncate-notched apex; upper glume exaristate or shortly aristate from the notch................................................................. C. copei
7. Lower glume of pedicelled spikelet not awned..................................................................................................................................8
7. Lower glume of pedicelled spikelet awned......................................................................................................................................10
8. Leaves up to 2.0 mm broad; upper glume of pedicelled spikelet awned; awn of upper lemma of sessile spikelet more than 4.5 cm long............................................................................................................................................................................. C. tadulingamii
8. Leaves more than 3 mm broad; upper glume of pedicelled spikelet awnless; awn of upper lemma of sessile spikelet less than 4.0 cm long ...............................................................................................................................................................................................9
9. Basal sheaths silky; leaf bladesca. 50 cm long, glabrous; sessile spikelets ca. 5.0 mm long; pedicelled spikelets 4.0–5.0 mm long..................................................................................................................................................................... C. pseudozeylanicus
9. Basal sheaths glabrous; leaf bladesca. 30 cm long, pubescent or pilose; sessile spikelets 5.0–8.0 mm long; pedicelled spikelets 7.0– 15 mm long (longest in the genus) ................................................................................................................... C. nodulibarbis
10. Leaves conspicuously distichous, often plicate; sheaths much compressed at the basal, acutely keeled, often beset with bulbousbased bristles .......................................................................................................................................................................... C. asper
10. Leaves not conspicuously distichous; sheaths rounded on back not keeled ....................................................................................11
11. Leaf blades convolute, panicle less than 12 cm long ................................................................................................... C. narayaniae
11. Leaf blades flat; panicle more than 12 cm long ...............................................................................................................................12
12. Culms slender; leaf blades less than 25 cm long; sessile spikelets hispidulous, 7.5–9.0 mm long................................. C. orientalis
12. Culms robust; leaf blades more than 25 cm long; sessile spikelets glabrous, 6.0–7.0 mm long......................................................13
13. Leaf blades less than 10 mm wide, margins scabrous; panicle ovoid or lanceolate, very dense; pedicelled spikelets more than 10 mm long; lower glume of pedicelled spikelet with 10–12 mm long arista .................................................................... C. hamiltonii
13. Leaf blades more than 10 mm wide, margins spinulose; panicle oblong, dense; pedicelled spikelets less than 10 mm long; lower glume of pedicelled spikelet with 5.0–7.0 mm long arista...............................................................................................................14
14. Leaves linear with long white hairs; ligule an eciliate membrane; sessile spikelets lanceolate, callus hairs red ........ C. verticillatus
14. Leaves narrowly-lanceolate, glabrous; ligule a fringe of hairs; sessile spikelets oblong, callus hairs dark brown ....... C. lancearius
15. Leaves puberulous............................................................................................................................................................................16
15. Leaves glabrous, occasionally with few tubercle-based hairs, not puberulous................................................................................17
16. Sheaths not strongly laterally compressed; leaf blade less than 4.0 mm wide, margins tuberculate-ciliate; pedicelled spikelets 6.0– 10 mm long, usually both the glumes with 4.0–7.0 mm long awned (sometimes lower glume exaristate);callus base of sessile spikelets acute..................................................................................................................................................................... C. aucheri
16. Sheaths very strongly laterally compressed with a prominent keel; leaf blade more than 4.0 mm wide, margins spinulose; pedicelled spikelets 5.0 mm long, both glumes always muticous; callus base of sessile spikelets truncate ..................................... C. velutinus
17. Leaves conspicuously distichous; panicle interrupted .....................................................................................................................18
17. Leaves not distichous; panicle oblong, not interrupted ....................................................................................................................19
18. Callus densely bearded throughout; pedicel and callus brownish hairy; upper glume of the sessile spikelets aristate, with an arista 4.0–8.0 mm long................................................................................................................................................. C. purushothamanii
18. Callus densely bearded at the base only; pedicel and callusfulvous hairy; upper glume of the sessile spikelets exaristate................ ...................................................................................................................................................................................... C. polyphyllus
19. Pedicelled spikelets shorter than the sessile, hairs chocolate-brown or rufous-brown; lower glume of pedicelled spikelets muticous ............................................................................................................................................................................. C. hackelii
19. Pedicelled spikelets equal or longer than the sessile, hairs golden or golden-brown; lower glume of pedicelled spikelets aristate ... ..........................................................................................................................................................................................................20
20. Upper glume of the sessile spikelets with a prominent dorsal tuft of brown hairs ............................................................... C. fulvus
20. Upper glume of the sessile spikelets without a dorsal tuft of hairs (if hairy then slightly but not brownish)..................................21
21. Peduncle glandular; panicle very dense ca. 15 × 8.0 (–10) cm with 35–76 racemes from lower nodes; upper lemma of pedicelled spikelet bifid and its palea reduced (ca. 1.0 mm long), acute, bidentate or irregularly tri-cuspidate.................. C. densipaniculatus
21. Peduncle eglandular; panicle not dense, 3.0–15 × 1.0– 2.5 cm, racemes less than 30 from the lower nodes; upper lemma of pedicelled spikelet and its palea (if present then not reduced) with acute apices.......................................................................... C. serrulatus
22. Lower glume of pedicelled spikelets distinctly aristate .................................................................................................... C. lawsonii
22. Lower glume of pedicelled spikelets exaristate................................................................................................................................23
23. Roots aromatic; apex of upper glume of the sessile spikelets muticous; upper lemma muticous or briefly awned (awns less than 2.0 mm long, enclosed......................................................................................................................................................... C. zizanioides
23. Roots not aromatic; apex of upper glume of the sessile spikelets mucronate (mucro 0.4 mm long); second lemma awned (awns exerted, 2.5–3.0 cm long).............................................................................................................................................. C. festucoides
description: Published as part of Tiwari, Arjun Prasad & Landge, Shahid Nawaz, 2022, Chrysopogon densipaniculatus (Poaceae: Andropogoneae): a new species from India, pp. 241-248 in Phytotaxa 538 (3) on pages 246-247, DOI: 10.11646/phytotaxa.538.3.7, http://zenodo.org/record/6336802