Holcus

L.
Treatment appears in FNA Volume 24. Treatment on page 739.
 TaxonIllustrator 
FNA24 P285A Holcus pg 741.jpegHolcus lanatusLinda Ann Vorobik
Hana Pazdírková

Plants usually perennial, rarely annual; cespitose or rhizomatous, rarely both cespitose and rhizomatous. Culms (8) 20-200 cm, glabrous or pubescent; nodes glabrous or retrorsely glabrous or puberulent; blade flat, pubescent. Inflorescences terminal panicles, contracted to open. Spikelets laterally compressed, with 2 (3) florets, lower florets bisexual, upper floret (s) staminate or sterile; rachillas curved below the lowest florets, sometimes prolonged beyond the base of the distal florets; disarticulation below the glumes. Glumes equaling to exceeding the florets, strongly keeled, unawned; upper lemmas awned from below the apices, awns hooked or geniculate; paleas thin, subequal to the lemmas; lodicules 2, glabrous, toothed or not; anthers 3; ovaries glabrous. Caryopses shorter than the lemmas, concealed at maturity, glabrous. x = 4, 7.

Distribution

Conn., N.J., N.Y., Del., N.C., Va., D.C, Wis., W.Va., Pacific Islands (Hawaii), Mass., Maine, N.H., R.I., Vt., Wash., Alta., B.C., N.B., Nfld. and Labr. (Labr.), N.S., Ont., Que., Sask., N.Mex., Tex., La., Tenn., S.C., Pa., Okla., Alaska, Nev., Puerto Rico, Colo., Md., Calif., Ala., Ark., Ill., Ga., Ind., Iowa, N.Dak., Ariz., Idaho, Mont., Oreg., Ohio, Utah, Mo., Mich., Kans., Miss., Ky.

Discussion

Holcus, a genus of eight species, is native to Europe, North Africa, and the Middle East. One species, H. lanatus, has become widely naturalized in the Americas, Japan, and Hawaii; a second, H. mollis, has become a troublesome weed in some areas of the Flora region.

Key

1 Awns 1-2 mm long, forming a curved hook at maturity; culms densely pilose adjacent to the lower nodes; plants cespitose, not rhizomatous Holcus lanatus
1 Awns 3-5 mm long, straight or geniculate at maturity; culms glabrous or sparsely pubescent adjacent to the lower nodes; plants not cespitose, rhizomatous Holcus mollis

"decumbent" is not a number.

... more about "Holcus"
membranous +  and scarious +
Lisa A. Standley +
1 (?) +  and 3 (?) +
straight +
basal +  and terminal +
geniculate +  and hooked +
keeled +  and rounded +
pseudopetiolate +  and branching +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
not evident +
cross +, linear +  and narrowly lanceolate +
spikelike +
hairy +  and glabrous +
not branching +
ascending +  and erect +
pubescent +  and glabrous +
20 cm200 mm <br />0.2 m <br /> (200 cm2,000 mm <br />2 m <br />) +
not woody +
Conn. +, N.J. +, N.Y. +, Del. +, N.C. +, Va. +, D.C +, Wis. +, W.Va. +, Pacific Islands (Hawaii) +, Mass. +, Maine +, N.H. +, R.I. +, Vt. +, Wash. +, Alta. +, B.C. +, N.B. +, Nfld. and Labr. (Labr.) +, N.S. +, Ont. +, Que. +, Sask. +, N.Mex. +, Tex. +, La. +, Tenn. +, S.C. +, Pa. +, Okla. +, Alaska +, Nev. +, Puerto Rico +, Colo. +, Md. +, Calif. +, Ala. +, Ark. +, Ill. +, Ga. +, Ind. +, Iowa +, N.Dak. +, Ariz. +, Idaho +, Mont. +, Oreg. +, Ohio +, Utah +, Mo. +, Mich. +, Kans. +, Miss. +  and Ky. +
1/4 +  and 1/3 +
liquid +, soft +  and hard +
capillary +
pistillate +  and staminate +
sometimes longer +
sterile +  and bisexual +
compressed +
reduced +
shorter or longer +
subtending +
unequal +
uncinate +
1-7(9)-veined +
lanceolate +  and ovate +
inconspicuous +
not +  and toothed +
concealed +  and prominent +
puberulent +  and glabrous +
2 +  and 1 +
well-developed +
2-keeled +
subequal +
spikelike +
dry +  and fleshy +
carroll1962a +, jones1958a +, jones1962a +  and zandee1982a +
1 +  and 60 +
compressed +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (5 cm50 mm <br />0.05 m <br />) +
1 +  and 3 +
simple +  and compound +
2 (?) +  and 3 (?) +
Gramineae +
Poaceae tribe Poeae +
membranous +
parallel +  and converging +
annual +  and perennial +
plant +  and cespitose +
aquatic +  and terrestrial +