Piptochaetium fimbriatum

(Kunth) Hitchc.
Common names: Pinyon ricegrass
Treatment appears in FNA Volume 24.
Please click on the illustration for a higher resolution version.
Illustrator: Cindy Roché

Copyright: Utah State University

Culms 35-95 cm, usually glabrous, sometimes pubescent below the nodes; nodes 2-3, often dark, glabrous. Sheaths glabrous, smooth; ligules truncate to rounded, of basal leaves 0.4-1.8 mm, of upper leaves 1.5-2 mm; blades 6-26 cm long, usually involute and 0.3-5 mm in diameter, sometimes flat and 0.5-1 (1.5) mm wide, 3-veined, both surfaces glabrous, veins often scabridulous, margins scabrous. Panicles 6.5-25 cm, open, often partially enclosed in the upper leaf-sheath, with 20-60 spikelets; branches flexuous; pedicels 4-12 mm, flattened, hispid. Glumes subequal, 4-6.2 mm long, 1.8-3.1 mm wide, 5-7-veined, often partly purplish; florets 3-5.5 mm long, 0.6-1.9 mm thick, somewhat laterally compressed, rectangular to slightly obovate in side view; calluses 0.2-0.7 mm, blunt, strigose; lemmas tan to light chocolate brown, shiny, smooth, evenly pubescent when immature, hairs easily rubbed off; crowns about 0.8 mm wide, inconspicuous, glabrous or glabrate; awns 11-20 mm, persistent, twice-geniculate; paleas about 3.5 mm; lodicules 2, about 1 mm; anthers 0.3-0.5 mm, not penicillate. Caryopses 2.5-3 mm long, about 0.6 mm thick, fusiform. 2n = 42.

Discussion

Piptochaetium fimbriatum is an attractive species that grows in oak and pinyon woods of the southwestern United States and adjacent Mexico, and merits consideration as an ornamental. It has also been reported from Guatemala; the report has not been verified.

Piptochaetium fimbriatum is not easily confused with other species in our range. Hitchcock (1951) treated it as including P. seleri (Pilg.) Henrard, a Mexican species with dull, rough, oblanceolate lemmas and persistent lemma hairs, an interpretation that is no longer accepted. It is occasionally confused with P. pringlei; it differs from that species in having shorter florets and blunt calluses.

Selected References

None.

Lower Taxa

None.

"decumbent" is not a number.

... more about "Piptochaetium fimbriatum"
membranous +  and scarious +
not penicillate +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
prow-tipped +  and sulcate +
awned +  and bifid +
Mary E. Barkworth +
(Kunth) Hitchc. +
twisted +  and not branched +
1 (?) +  and 3 (?) +
subterminal +  and eccentric +
2 times-geniculate +
1.1 cm11 mm <br />0.011 m <br /> (2 cm20 mm <br />0.02 m <br />) +
keeled +  and rounded +
pseudopetiolate +  and branching +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
6 cm60 mm <br />0.06 m <br /> (26 cm260 mm <br />0.26 m <br />) +
not evident +
convolute +  and flat +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
spikelike +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.07 cm0.7 mm <br />7.0e-4 m <br />) +
Pinyon ricegrass +
glabrate +  and glabrous +
branching +  and not branched +
perennial +  and annual +
intravaginal +  and basal +
pubescent +  and glabrous +
35 cm350 mm <br />0.35 m <br /> (95 cm950 mm <br />0.95 m <br />) +
not woody +
Ariz. +, N.Mex. +  and Tex. +
0 +  and 1/3 +
liquid +, soft +  and hard +
capillary +
pistillate +  and staminate +
0.3 cm3 mm <br />0.003 m <br /> (0.55 cm5.5 mm <br />0.0055 m <br />) +
sometimes longer +
rectangular +  and slightly obovate +
4mm +  and 6.2mm +
subtending +
lanceolate +
subequal +
membranous +
1.8mm +  and 3.1mm +
yellow +  and golden brown +
uncinate +
0.2 cm2 mm <br />0.002 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
solid +  and hollow +
basally concentrated +  and evenly distributed +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
brown +, tan +  and light chocolate +
papillate +  and tuberculate +
narrowed +
coriaceous +  and indurate +
truncate +  and acute +
membranous +
inconspicuous +
acute +  and blunt +
1 cm10 mm <br />0.01 m <br /> (?) +
scabridulous +
concealed +  and prominent +
2 +  and 3 +
2 +  and 1 +
well-developed +
reduced +
3.5 cm35 mm <br />0.035 m <br /> (?) +
6.5 cm65 mm <br />0.065 m <br /> (25 cm250 mm <br />0.25 m <br />) +
flattened +
0.4 cm4 mm <br />0.004 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
dry +  and fleshy +
not prolonged +
20 +  and 60 +
unisexual +  and bisexual +
laterally compressed +  and terete +
0.4 cm4 mm <br />0.004 m <br /> (2.2 cm22 mm <br />0.022 m <br />) +
1 +  and 3 +
simple +  and compound +
2 (?) +  and 3 (?) +
scabridulous +
Gramineae +
Piptochaetium fimbriatum +
Piptochaetium +
species +
membranous +
0.1 cm1 mm <br />0.001 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
inconspicuous +
scabridulous +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
plant +  and cespitose +
aquatic +  and terrestrial +