Piptatherum racemosum

(Sm.) Eaton
Common names: Mountain ricegrass
Synonyms: Oryzopsis racemosa
Treatment appears in FNA Volume 24. Treatment on page 148.

Plants loosely cespitose to soboliferous, rhizomatous. Culms 48-80 cm, scabrous or pubescent adjacent to the nodes; basal branching extravaginal. Leaves not basally concentrated; sheaths usually smooth and glabrous, occasionally scabridulous and inconspicuously pubescent near the margins; ligules of upper leaves 0.3-0.7 mm, truncate; blades of basal leaves 0-2 cm; blades of upper leaves 10-27 cm long, 8-16 mm wide, abaxial surfaces evenly but sparsely pubescent, adaxial surfaces with straight hairs to 0.3 mm on the primary-veins and flexuous hairs of 0.5-0.9 mm on the minor veins, tapering from near midlength to the apices. Panicles 12-25 cm, lower nodes with 1-2 branches; branches 3-9.5 cm, straight, strongly ascending to strongly divergent, with 2-5 spikelets. Glumes 6-8 mm, from subequal to the florets to exceeding the florets by 2 mm, ovate, 5-7-veined, acuminate; florets 4.5-7.5 mm; calluses 0.3-0.6 mm, disarticulation scars circular; lemmas coriaceous, sparsely pubescent to glabrate throughout, margins fused at the base, not overlapping, shiny dark-brown to black at maturity; awns 10-25 mm, deciduous, slightly twisted, flexuous; anthers 3.5-5.5 mm, not penicillate; ovaries developing 2 conelike extensions, each terminating in a style. Caryopses 5-6 mm; hila linear, 4/5 – 9/10 as long as the caryopses. 2n = 46,48.

Discussion

Piptatherum racemosum usually grows in deciduous woods, and less often in open pine woods, in rocky, mountainous areas, from the St. Lawrence and Ottawa rivers south to the Missouri River, Tennessee, and Virginia, and east to Maine. The absence of basal blades and the dark, shiny lemmas distinguish it from all other North American Stipeae. It is highly palatable to livestock, but is never sufficiently abundant to be important as forage.

Selected References

None.

Lower Taxa

None.

"decumbent" is not a number."prolonged" is not a number.

... more about "Piptatherum racemosum"
membranous +  and scarious +
not penicillate +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.55 cm5.5 mm <br />0.0055 m <br />) +
awned +, bifid +, bilobed +  and entire +
not stiff +
hairy +  and glabrous +
Mary E. Barkworth +
(Sm.) Eaton +
1 (?) +  and 3 (?) +
20 cm200 mm <br />0.2 m <br /> (?) +
flexuous +
subterminal +  and eccentric +
2 times-geniculate scabrous +
1 cm10 mm <br />0.01 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
keeled +  and rounded +
not branching +
extravaginal +
swelling +
not evident +
tapering +
0.5mm;16mm +
spikelike +
well-developed +
with hairs +  and glabrous +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.06 cm0.6 mm <br />6.0e-4 m <br />) +
Mountain ricegrass +
perennial +  and annual +
extravaginal +  and basal +
48 cm480 mm <br />0.48 m <br /> (80 cm800 mm <br />0.8 m <br />) +
not woody +
Md. +, N.J. +, Utah +, Calif. +, Pa. +, Ariz. +, Idaho +  and Nev. +
0 +  and 1/3 +
liquid +, soft +  and hard +
capillary +
pistillate +  and staminate +
sometimes longer +
terete +  and compressed +
4.5mm +  and 7.5mm +
1-10-veined +
subtending +
acuminate +  and ovate +
subequal +
2 cm20 mm <br />0.02 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
membranous +
flexuous +  and straight +
not spreading +
tapering +
0 cm0 mm <br />0 m <br /> (0.03 cm0.3 mm <br />3.0e-4 m <br />) +
4/5 +  and 9/10 +
3 cm30 mm <br />0.03 m <br /> (40 cm400 mm <br />0.4 m <br />) +
solid +  and hollow +
basally concentrated +  and evenly distributed +
10 cm100 mm <br />0.1 m <br /> (27 cm270 mm <br />0.27 m <br />) +
0 cm0 mm <br />0 m <br /> (2 cm20 mm <br />0.02 m <br />) +
0.8 cm8 mm <br />0.008 m <br /> (1.6 cm16 mm <br />0.016 m <br />) +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.07 cm0.7 mm <br />7.0e-4 m <br />) +
light-brown +  and black +
sparsely pubescent +  and glabrate +
ovate +, rectangular +  and lanceolate +
0.12 cm1.2 mm <br />0.0012 m <br /> (0.9 cm9 mm <br />0.009 m <br />) +
coriaceous +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
membranous +
inconspicuous +
lanceolate +
fleshy +  and membranous +
not overlapping +
dark-brown +  and black +
concealed +  and prominent +
1 +  and 6 +
2 +  and 1 +
pubescent +  and glabrous +
well-developed +
2(3)-veined +
not keeled +
reduced +
12 cm120 mm <br />0.12 m <br /> (25 cm250 mm <br />0.25 m <br />) +
dry +  and fleshy +
not prolonged +
pubescent +  and glabrous +
smooth to scabrous +
scabridulous +
unisexual +  and bisexual +
laterally compressed +  and terete +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.75 cm7.5 mm <br />0.0075 m <br />) +
1 (?) +  and 3 (?) +
simple +  and compound +
2 (?) +  and 3 (?) +
Oryzopsis racemosa +
Piptatherum racemosum +
Piptatherum +
species +
membranous +
rhizomatous +  and soboliferous +
plant +  and cespitose +
aquatic +  and terrestrial +