Triplasis

P. Beauv.
Treatment appears in FNA Volume 25. Treatment on page 41.
 TaxonIllustrator 
FNA25 P13B Triplasis pg 43.jpegTriplasis purpureaKaren Klitz
Linda A. Vorobik

Plants annual or perennial; cespitose, occasionally rhizomatous. Culms 14-100 cm, ascending to erect; nodes pubescent to hirsute. Sheaths open; auricles absent; ligules of hairs or membranous and ciliate; blades 1-5 mm wide, flat or involute. Primary inflorescences terminal, open panicles, with few spikelets, exerted or partially included in the upper sheath, apices exceeding the upper leaf-blades, axillary panicles sometimes also present; cleistogamous inflorescences also present in the upper sheaths. Spikelets laterally compressed, purplish, with 2-5 florets; sterile florets above the fertile florets; rachillas prolonged; disarticulation above the glumes and beneath the florets and, subsequently, at the cauline nodes. Glumes equal or unequal, shorter than the first lemma, 1-veined, keeled; calluses hairy; lemmas 3-veined, veins villous, apices bilobed to incised, midveins sometimes extending into an awn, awns to 11 mm; paleas bowed-out, keels hairy, distal hairs 0.5-2 mm, longer than those below; lodicules 2, truncate; anthers 3, yellow or reddish-purple; stigmas pink to purple. Caryopses dorsiventrally compressed, x = 10.

Distribution

Conn., N.J., N.Y., Del., Wis., Fla., N.H., N.Mex., Tex., La., Tenn., N.C., S.C., Pa., Va., Colo., Ont., Ala., Kans., N.Dak., Nebr., Okla., S.Dak., Ark., Ill., Ga., Ind., Iowa, Ky., Maine, Md., Mass., Ohio, Mo., Mich., R.I., Miss., Oreg.

Discussion

Triplasis is an American genus of two species that is probably related to Tridens. The disarticulating culm, which helps disperse the cleistogenes, aids in distinguishing Triplasis from other genera.

Selected References

None.

Key

1 Lemmas with lobes 4.5-8 mm long, tapering to acute tips; lemma awns 5-11 mm long; culm internodes puberulent to pilose Triplasis americana
1 Lemmas with lobes about 1 mm long, rounded; lemma awns less than 2 mm long; culm internodes glabrous Triplasis purpurea

"decumbent" is not a number.

... more about "Triplasis"
reddish-purple +  and yellow +
bilobed +  and incised +
Stephan L. Hatch +
P. Beauv. +
1 (?) +  and 3 (?) +
multiple +, , +  and single +
0 cm0 mm <br />0 m <br /> (1.1 cm11 mm <br />0.011 m <br />) +
keeled +  and rounded +
pseudopetiolate +  and branching +
not fused +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
membranous +
not pseudopetiolate +
pubescent +  and glabrous +
involute +  and flat +
0.1 cm1 mm <br />0.001 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
spikelike +
compressed +
triangular +  and dome--shaped +
sometimes longer +
membranous +
ascending +  and erect +
14 cm140 mm <br />0.14 m <br /> (100 cm1,000 mm <br />1 m <br />) +
not woody +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
Conn. +, N.J. +, N.Y. +, Del. +, Wis. +, Fla. +, N.H. +, N.Mex. +, Tex. +, La. +, Tenn. +, N.C. +, S.C. +, Pa. +, Va. +, Colo. +, Ont. +, Ala. +, Kans. +, N.Dak. +, Nebr. +, Okla. +, S.Dak. +, Ark. +, Ill. +, Ga. +, Ind. +, Iowa +, Ky. +, Maine +, Md. +, Mass. +, Ohio +, Mo. +, Mich. +, R.I. +, Miss. +  and Oreg. +
not waisted +
capillary +
pistillate +  and staminate +
sometimes longer +
2 +  and 5 +
fertile +  and sterile +
round +  and compressed +
reduced +
shorter or longer +
subtending +
unequal +
uncinate +
paniculate +  and racemose +
hollow +  and solid +
not absent +
sometimes longer +
membranous +
inconspicuous +
concealed +  and prominent +
pubescent +  and hirsute +
2 +  and 1 +
dry +  and fleshy +
spikelike +
compressed +
1 +  and 3 +
compound +  and simple +
pink +  and purple +
2 (?) +  and 3 (?) +
Gramineae +
Triplasis +
Poaceae tribe Cynodonteae +
membranous +
7 (?) +  and 13 (?) +
perennial +  and annual +
plant +  and cespitose +
aquatic +  and terrestrial +
dioecious +, monoecious +  and synoecious +