Piptochaetium stipoides

(Trin. & Rupr.) Hack.
Common names: Stipoid ricegrass
Synonyms: Piptochaetium stipoides var. purpurascens
Treatment appears in FNA Volume 24. Treatment on page 166.
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Illustrator: Cindy Roché

Copyright: Utah State University

Culms 20-60 cm, erect to ascending; nodes 2-4, dark, glabrous. Sheaths glabrous or hispidulous towards the collar; ligules 0.8-2 mm, glabrous, abaxial surfaces scabridulous, margins occasionally ciliate; blades (5) 14-30 cm long, 0.2-0.4 mm wide, linear, glabrous or villous, margins scabridulous. Panicles 4-15 cm long, 1.5-3 cm wide, with 10-70 spikelets; branches ascending, scabridulous; pedicels 1-11 mm, hispid. Glumes subequal, 4-8.5 mm long, 1.5-2 mm wide, purple towards the base, glabrous, 5-veined, apices aristulate; florets 2.3-4 (5) mm long, 0.8-2.3 mm thick, obovoid, globose to laterally compressed; calluses 0.5-0.6 mm, blunt, hairs white to golden tan; lemmas shiny, glabrous, striate, dark-brown to black at maturity, wholly smooth to conspicuously verrucose or sharply papillose, at least distally, constricted below the crown; crowns well-developed, 0.6-1.6 mm wide, distal margins slightly to strongly revolute, inner surfaces densely covered with hooks and hairs; awns 15-25 mm, eccentric, twice-geniculate, tardily deciduous; paleas 2.5-5 mm; lodicules 2, linear; anthers about 0.5 mm. Caryopses 1.5-2.5 mm, spherical to ellipsoid. 2n = unknown.

Discussion

Piptochaetium stipoides is native to South America. There is one known population in the Flora region, in Marin County, California, which grows with P. setosum in a meadow adjacent to an old dirt road. The origin of the population is not known; it has been suggested that the seeds might have been brought in by birds, as the area was a bird refuge at one time.

The Californian plants belong to Piptochaetium stipoides (Trin. & Rupr.) Hack. var. stipoides, which differs from the only other variety recognized by Cialdella and Arriaga (1998), P. stipoides var. echinulatum Parodi, in having lemmas that are mostly smooth as well as a less revolute crown.

Selected References

None.

Lower Taxa

None.

"decumbent" is not a number.

... more about "Piptochaetium stipoides"
membranous +  and scarious +
0.5 cm5 mm <br />0.005 m <br /> (?) +
prow-tipped +  and sulcate +
awned +  and bifid +
aristulate +
Mary E. Barkworth +
(Trin. & Rupr.) Hack. +
twisted +  and not branched +
1 (?) +  and 3 (?) +
eccentric +
1.5 cm15 mm <br />0.015 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
keeled +  and rounded +
pseudopetiolate +  and branching +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
14 cm140 mm <br />0.14 m <br /> (30 cm300 mm <br />0.3 m <br />) +
not evident +
villous +  and glabrous +
convolute +  and flat +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.04 cm0.4 mm <br />4.0e-4 m <br />) +
scabridulous +
spikelike +
strigose +  and glabrous +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.06 cm0.6 mm <br />6.0e-4 m <br />) +
Stipoid ricegrass +
branching +  and not branched +
perennial +  and annual +
erect +  and ascending +
intravaginal +  and basal +
20 cm200 mm <br />0.2 m <br /> (60 cm600 mm <br />0.6 m <br />) +
not woody +
0 +  and 1/3 +
liquid +, soft +  and hard +
capillary +
pistillate +  and staminate +
0.23 cm2.3 mm <br />0.0023 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
sometimes longer +
globose +  and laterally compressed +
4mm +  and 8.5mm +
subtending +
lanceolate +
subequal +
membranous +
1.5mm +  and 2mm +
white +  and golden tan +
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 +
dark-brown +  and black +
wholly smooth +  and conspicuously verrucose or sharply papillose +
narrowed +
constricted +
coriaceous +  and indurate +
truncate +  and acute +
0.08 cm0.8 mm <br />8.0e-4 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
membranous +
inconspicuous +
acute +  and blunt +
scabridulous +
concealed +  and prominent +
2 +  and 4 +
2 +  and 1 +
well-developed +
reduced +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
4cm +  and 15cm +
1.5 cm15 mm <br />0.015 m <br /> (3 cm30 mm <br />0.03 m <br />) +
0.1 cm1 mm <br />0.001 m <br /> (1.1 cm11 mm <br />0.011 m <br />) +
dry +  and fleshy +
not prolonged +
hispidulous +  and glabrous +
10 +  and 70 +
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 (?) +
Piptochaetium stipoides var. purpurascens +
Piptochaetium stipoides +
Piptochaetium +
species +
membranous +
0.1 cm1 mm <br />0.001 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
prow-tipped +  and sulcate +
inconspicuous +
plant +  and cespitose +
aquatic +  and terrestrial +