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purpletop, purpletop tridens

Photo is of parent taxon

purpletop tridens

Habit Plants with firm, knotty, shortly rhizomatous bases.
Culms

60-180 cm.

Sheaths

keeled, mostly glabrous, collars pubescent;

ligules to 0.5 mm, membranous, ciliate;

blades 3-10 mm wide, glabrous or sparsely hispid, apices attenuate and involute.

Panicles

15-40 cm long, 3-5 cm wide, erect or nodding;

branches 10-15(25) cm, strongly divergent to drooping, stiff or lax, lower branches naked for 1/3 – 1/2 of their length;

pedicels 3-8 mm.

nodding distally;

branches flexible;

pulvini inconspicuously or conspicuously hairy, hairs confined to the adaxial side of the branches.

Spikelets

5-10 mm long, with 4-8 florets.

Lower glumes

2.5-3 mm, often mucronate;

upper glumes 3.5-4 mm;

lemmas 3-5 mm, lateral veins puberulent or ciliate to well above midlength, midveins and lateral veins usually excurrent, midveins extending to 0.5 mm, lateral vein extensions shorter;

paleas as long as the lemmas, widened below;

anthers 1-1.5 mm.

Caryopses

1.8-2 mm.

2n

= 40.

Tridens flavus

Tridens flavus var. flavus

Distribution
from FNA
AL; AR; CA; CT; DC; DE; FL; GA; IA; IL; IN; KS; KY; LA; MA; MD; MI; MN; MO; MS; NC; NE; NH; NJ; NM; NY; OH; OK; PA; RI; SC; TN; TX; VA; VT; WI; WV; ON
[WildflowerSearch map]
[BONAP county map]
from FNA
AL; AR; CA; CT; DC; DE; FL; GA; IA; IL; IN; KS; KY; LA; MA; MD; MI; MN; MO; MS; NC; NE; NH; NJ; NM; NY; OH; OK; PA; RI; SC; TN; TX; VA; VT; WI; WV; ON
[BONAP county map]
Discussion

Tridens flavus var. flavus grows in old fields and open woods. Its range extends to Nuevo Léon, Mexico. It was discovered for the first time in Canada in 1976, growing along a railway track in southern Ontario.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Key
1. Panicles nodding; pulvini inconspicuously or conspicuously hairy, the hairs confined to the adaxial side of the branches
var. flavus
1. Panicles erect throughout; pulvini always conspicuously hairy, the hairs extending around the base of the branches
var. chapmanii
Source FNA vol. 25, p. 39. FNA vol. 25, p. 39.
Parent taxa Poaceae > subfam. Chloridoideae > tribe Cynodonteae > Tridens Poaceae > subfam. Chloridoideae > tribe Cynodonteae > Tridens > Tridens flavus
Sibling taxa
T. albescens, T. ambiguus, T. buckleyanus, T. carolinianus, T. congestus, T. eragrostoides, T. muticus, T. strictus, T. texanus
T. flavus var. chapmanii
Subordinate taxa
T. flavus var. chapmanii, T. flavus var. flavus
Synonyms Triodia sesleroidies, Triodia flava, T. flavus forma cupreus, Poa flava
Name authority (L.) Hitchc. unknown
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