Jarava speciosa

(Trin. & Rupr.) Penail.
Common names: Desert needlegrass
Synonyms: Stipa speciosa Achnatherum speciosum
Treatment appears in FNA Volume 24. Treatment on page 181.
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Plants tightly cespitose, not rhizomatous. Culms 30-60 cm, bases orangebrown; nodes 3-6; basal branching intravaginal. Sheaths mostly glabrous, throats densely ciliate, basal sheaths reddish-brown, flat and ribbonlike with age; ligules varying within a plant, lower ligules 0.3-1 mm, densely hairy and ciliate, hairs 0.2-1 mm, often longer than the basal membrane, upper ligules to 2.5 mm, hyaline to scarious, glabrous or hairy, usually less hairy than the lower ligules, sometimes ciliate; blades 10-30 cm long, 0.5-2 mm wide when flat, usually rolled, to 1 mm in diameter, abaxial surfaces glabrous, smooth, adaxial surfaces pilose. Panicles 10-15 cm, dense, frequently partially included in the upper leaf-sheaths at maturity; branches ascending. Spikelets 16-24 mm. Glumes linear-lanceolate, glabrous, tapering from below midlength to the narrowly acute apices; lower glumes 16-24 mm, 1-veined; upper glumes 13-19 mm, 3-5-veined; florets (6) 8-10 mm; calluses 0.8-1.6 (3) mm, sharp; lemmas densely and evenly hairy, hairs about 0.5 mm, without a pappus; awns 35-45 (80) mm, once-geniculate, first segment pilose, hairs 3-8 mm, terminal segment glabrous, smooth; paleas 3.2-5.1 mm, 2/5 – 2/3 (4/5) the length of the lemmas, usually hairy, hairs about 0.5 mm. 2n = 66, 68, about 74.

Discussion

Jarava speciosa grows on rocky slopes in canyons of arid and semiarid regions of the southwestern United States and northern Mexico, and in Chile and northern to central Argentina. Several varieties are recognized in South America. It is not clear to which of these varieties, if any, the North American plants belong.

The reddish brown leaf bases, differing lower and upper ligules, and the pilose, once-geniculate awns make Jarava speciosa an easy species to recognize in North America. It is also an attractive species, well worth cultivating. It prefers open areas with well-drained soils. The growth of young shoots and flowering is stimulated by fire.

Selected References

None.

Lower Taxa

None.

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

... more about "Jarava speciosa"
74 +, 68 +  and 66 +
membranous +  and scarious +
awned +, bifid +, bilobed +  and entire +
Mirta O. Arriaga +
(Trin. & Rupr.) Penail. +
twisted +  and not branched +
1 (?) +  and 3 (?) +
80 cm800 mm <br />0.8 m <br /> (?) +
subterminal +  and eccentric +
pilose +  and scabrous +
once-geniculate +
3.5 cm35 mm <br />0.035 m <br /> (4.5 cm45 mm <br />0.045 m <br />) +
keeled +  and rounded +
pseudopetiolate +  and branching +
orangebrown +
intravaginal +, extravaginal +, branching +  and basal +
knotted +
swelling +
10 cm100 mm <br />0.1 m <br /> (30 cm300 mm <br />0.3 m <br />) +
not evident +
0 cm0 mm <br />0 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
spikelike +
well-developed +
0.08 cm0.8 mm <br />8.0e-4 m <br /> (0.16 cm1.6 mm <br />0.0016 m <br />) +
Desert needlegrass +
not branching +
perennial +  and annual +
ascending +  and erect +
extravaginal +, intravaginal +, branching +  and basal +
30 cm300 mm <br />0.3 m <br /> (60 cm600 mm <br />0.6 m <br />) +
not woody +
0 +  and 1/3 +
liquid +, soft +  and hard +
capillary +
pistillate +  and staminate +
sometimes longer +
terete +  and lanceoloid +
8mm +  and 10mm +
1-10-veined +
usually longer +
subtending +
tapering +  and linear-lanceolate +
unequal +
membranous +
uncinate +
0.5 cm5 mm <br />0.005 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
solid +  and hollow +
basally concentrated +  and evenly distributed +
10 cm100 mm <br />0.1 m <br /> (?) +
1/3 +  and 2/3 +
ovate +, rectangular +  and lanceolate +
0.3 cm3 mm <br />0.003 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
membranous +
hairy +  and glabrous +
membranous +
inconspicuous +
lanceolate +
fleshy +  and membranous +
1.6 cm16 mm <br />0.016 m <br /> (2.4 cm24 mm <br />0.024 m <br />) +
concealed +  and prominent +
3 +  and 6 +
2 +  and 1 +
pubescent +  and glabrous +
well-developed +
pubescent +  and glabrous +
2/5 +  and 2/34/5 +
reduced +
0.32 cm3.2 mm <br />0.0032 m <br /> (0.51 cm5.1 mm <br />0.0051 m <br />) +
membranous +
10 cm100 mm <br />0.1 m <br /> (15 cm150 mm <br />0.15 m <br />) +
dry +  and fleshy +
not prolonged +
1 +  and 60 +
unisexual +  and bisexual +
laterally compressed +  and terete +
1.6 cm16 mm <br />0.016 m <br /> (2.4 cm24 mm <br />0.024 m <br />) +
1 +  and 3 +
simple +  and compound +
2 (?) +  and 3 (?) +
Stipa speciosa +  and Achnatherum speciosum +
Jarava speciosa +
species +
membranous +
1.3 cm13 mm <br />0.013 m <br /> (1.9 cm19 mm <br />0.019 m <br />) +
inconspicuous +
plant +  and cespitose +
aquatic +  and terrestrial +
12 +, 11 +, 10 +, 8 +  and 7 +