Piptatherum exiguum

(Thurb.) Dorn
Common names: Little piptatherum
Synonyms: Oryzopsis exigua
Treatment appears in FNA Volume 24. Treatment on page 146.

Plants tightly cespitose, not rhizomatous. Culms 12-40 cm, sometimes not exceeding the basal leaves, scabridulous; basal branching mostly intravaginal. Leaves basally concentrated; sheaths mostly smooth, some¬times scabridulous distally; ligules 1.2-3.5 mm, acute; basal blades 9-30 cm long, 0.6-1.4 mm wide when open, usually valvate and 0.4-0.8 mm in diameter, both surfaces scabrous. Panicles 3.5-9 cm, lower nodes with 1-2 branches; branches straight, tightly appressed to the rachises, lower branches 1-2 cm, with 1-2 spikelets. Glumes subequal, 3.5-6 mm long, 1.8-2.2 mm wide, ovate, apices acute; florets 3-6 mm, terete; calluses 0.2-0.5 mm, hirsute, disarticulation scars circular; lemmas evenly pubescent, tan or gray-brown at maturity, margins not overlapping at maturity, apical lobes 2, 0.3-0.4 mm, thick; awns 3.9-7 mm, persistent, strongly once-geniculate, basal segment twisted; paleas not exceeding the lemma lobes, similar in texture and pubescence; anthers 1.5-3 mm; ovaries with a conelike extension bearing a 3-branched style. Caryopses about 2.5 mm long, 1 mm thick; hila linear, 9/10 as long as to equaling the caryopses. 2n = 22.

Discussion

Piptatherum exiguum grows on rocky slopes and outcrops in upper montane habitats, from central British Columbia to southwestern Alberta and south to northern California, Nevada, Utah, and northern Colorado. The limited DNA evidence available suggests that it is a basal species within Piptatherum (Jacobs et al. 2006).

Selected References

None.

Lower Taxa

None.

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

... more about "Piptatherum exiguum"
membranous +  and scarious +
penicillate +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
awned +, bifid +, bilobed +  and entire +
not stiff +
hairy +  and glabrous +
Mary E. Barkworth +
(Thurb.) Dorn +
twisted +  and not branched +
1 (?) +  and 3 (?) +
20 cm200 mm <br />0.2 m <br /> (?) +
straight +
subterminal +  and eccentric +
2 times-geniculate scabrous +
once-geniculate +
0.39 cm3.9 mm <br />0.0039 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
keeled +  and rounded +
9 cm90 mm <br />0.09 m <br /> (30 cm300 mm <br />0.3 m <br />) +
0.06 cm0.6 mm <br />6.0e-4 m <br /> (0.14 cm1.4 mm <br />0.0014 m <br />) +
not branching +
extravaginal +
swelling +
not evident +
tapering +
0.5mm;16mm +
spikelike +
well-developed +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
Little piptatherum +
perennial +  and annual +
intravaginal +  and basal +
12 cm120 mm <br />0.12 m <br /> (40 cm400 mm <br />0.4 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 +
3.5mm +  and 6mm +
subtending +
subequal +
membranous +
1.8mm +  and 2.2mm +
not spreading +
uncinate +
0.5 cm5 mm <br />0.005 m <br /> (?) +
3 cm30 mm <br />0.03 m <br /> (40 cm400 mm <br />0.4 m <br />) +
solid +  and hollow +
basally concentrated +  and evenly distributed +
gray-brown +  and tan +
ovate +, rectangular +  and lanceolate +
0.12 cm1.2 mm <br />0.0012 m <br /> (0.9 cm9 mm <br />0.009 m <br />) +
membranous +  and coriaceous +
0.12 cm1.2 mm <br />0.0012 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
membranous +
inconspicuous +
lanceolate +
fleshy +  and membranous +
1 cm10 mm <br />0.01 m <br /> (2 cm20 mm <br />0.02 m <br />) +
not overlapping +
concealed +  and prominent +
1 +  and 6 +
2 +  and 1 +
pubescent +  and glabrous +
well-developed +
2(3)-veined +
not keeled +
reduced +
3.5 cm35 mm <br />0.035 m <br /> (9 cm90 mm <br />0.09 m <br />) +
dry +  and fleshy +
not prolonged +
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 exigua +
Piptatherum exiguum +
Piptatherum +
species +
membranous +
plant +  and cespitose +
aquatic +  and terrestrial +