Piptochaetium stipoides |
Piptochaetium fimbriatum |
|
---|---|---|
purple spear grass, stipoid ricegrass |
pinon ricegrass, pinyon ricegrass |
|
Culms | 20-60 cm, erect to ascending; nodes 2-4, dark, glabrous. |
35-95 cm, usually glabrous, sometimes pubescent below the nodes; nodes 2-3, often 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. |
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 | 4-15 cm long, 1.5-3 cm wide, with 10-70 spikelets; branches ascending, scabridulous; pedicels 1-11 mm, hispid. |
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, 4-8.5 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. |
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 | 1.5-2.5 mm, spherical to ellipsoid. |
2.5-3 mm long, about 0.6 mm thick, fusiform. |
2n | = unknown. |
= 42. |
Piptochaetium stipoides |
Piptochaetium fimbriatum |
|
Distribution |
CA
|
AZ; NM; TX
|
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. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 24, p. 166. | FNA vol. 24. |
Parent taxa | Poaceae > subfam. Pooideae > tribe Stipeae > Piptochaetium | Poaceae > subfam. Pooideae > tribe Stipeae > Piptochaetium |
Sibling taxa | ||
Synonyms | P. stipoides var. purpurascens | |
Name authority | (Trin. & Rupr.) Hack. | (Kunth) Hitchc. |
Web links |