Podagrostis humilis

(Vasey) Bjorkman
Common names: Alpine bent
Endemic
Synonyms: Podagrostis thurberiana Agrostis thurberiana Agrostis humilis
Treatment appears in FNA Volume 24. Treatment on page 694.
Please click on the illustration for a higher resolution version.
Illustrator: Sandy Long

Copyright: Utah State University

Plants sometimes rhizomatous. Culms 5-50 cm, erect to ascending, bases sometimes somewhat decumbent; nodes 2-4 (7). Sheaths smooth; ligules (0.2) 0.5-2 (2.7) mm, scabridulous, truncate to obtuse, usually erose to lacerate, sometimes entire; blades 2-15 cm long, 1-4 mm wide, flat or involute; flag blades at about midculm. Panicles 1.5-14 cm long, 0.4-2.5 cm wide, narrowly oblong to ovate, somewhat lax, sometimes drooping, lowest nodes with 1-4 (5) branches; branches scabridulous or smooth, loosely ascending to erect, branching in the distal 1/3 – 3/4; lower branches 0.5-7 cm; pedicels 0.4-4 mm. Spikelets ovate to lanceolate, green to purple; rachilla prolongations 0.1-0.6 mm, glabrous or bristlelike, with a tuft of short hairs at the apex. Glumes 1.6-2.3 mm, 1-veined, veins smooth or slightly scabrous distally, apices acute; lower glumes equal to or longer than the upper glumes; calluses glabrous or with sparse hairs to 0.5 mm; lemmas 1.5-2.3 mm, relatively thick, smooth, opaque, 5-veined, veins obscure or prominent at the apices, apices truncate to rounded or acute, entire or erose, veins occasionally minutely excurrent to 0.4 mm, usually unawned, rarely awned, awns to about 1.3 mm, usually subapical, sometimes attached near midlength; paleas 0.9-1.6 mm; anthers 3, 0.4-0.8 mm. Caryopses 1-1.3 mm. 2n = 14.

Discussion

Podagrostis humilis is a western North American species that grows in undisturbed alpine and subalpine meadows and screes at over 3500 m, down to meadows, fens, and open woodlands at less than 200 m.

As treated here, Podagrostis humilis includes P. thurberiana (Hitchc.) Hulten, a species that supposedly differs in having larger, more open panicles and wider leaves; there is complete intergradation between the two extremes. There is similar but less severe intergradation with P. aequivalvis. In the field, dwarf forms of P. humilis mimic Agrostis variabilis; they differ from that species in having paleas.

Selected References

None.

Lower Taxa

None.

"decumbent" is not a number.

... more about "Podagrostis humilis"
membranous +  and scarious +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (0.08 cm0.8 mm <br />8.0e-4 m <br />) +
erose +  and entire +
with hairs +  and glabrous +
M.J. Harvey +
(Vasey) Bjorkman +
1 (?) +  and 3 (?) +
straight +
attached +
basal +  and terminal +
keeled +  and rounded +
pseudopetiolate +  and branching +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
2 cm20 mm <br />0.02 m <br /> (15 cm150 mm <br />0.15 m <br />) +
not evident +
involute +  and flat +
1mm;4mm +
loosely ascending;erect +
smooth +  and scabridulous +
spikelike +
with sparse hairs +  and glabrous +
Alpine bent +
not branching +
erect +  and ascending +
5 cm50 mm <br />0.05 m <br /> (50 cm500 mm <br />0.5 m <br />) +
not woody +
1/4 +  and 1/3 +
liquid +, soft +  and hard +
capillary +
pistillate +  and staminate +
sometimes longer +
sterile +  and bisexual +
compressed +
reduced +
shorter or longer +
subtending +
unequal +
0.16 cm1.6 mm <br />0.0016 m <br /> (0.23 cm2.3 mm <br />0.0023 m <br />) +
uncinate +
0 cm0 mm <br />0 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
lanceolate +  and ovate +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.23 cm2.3 mm <br />0.0023 m <br />) +
membranous +
lacerate +, truncate +  and obtuse +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
membranous +
inconspicuous +
lanceolate +
0.5 cm5 mm <br />0.005 m <br /> (7 cm70 mm <br />0.07 m <br />) +
acute +  and acuminate +
concealed +  and prominent +
2 +  and 4 +
2 +  and 1 +
hairy +  and glabrous +
well-developed +
/2 +  and 1 +
2-keeled +
0.09 cm0.9 mm <br />9.0e-4 m <br /> (0.16 cm1.6 mm <br />0.0016 m <br />) +
thinner +
1.5cm +  and 14cm +
narrowly oblong +  and ovate +
0.4 cm4 mm <br />0.004 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
dry +  and fleshy +
green +  and purple +
1 +  and 60 +
ovate +  and lanceolate +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (5 cm50 mm <br />0.05 m <br />) +
1 (?) +  and 3 (?) +
simple +  and compound +
2 (?) +  and 3 (?) +
Podagrostis thurberiana +, Agrostis thurberiana +  and Agrostis humilis +
Podagrostis humilis +
Podagrostis +
species +
membranous +
parallel +  and converging +
prominent +  and obscure +
0 cm0 mm <br />0 m <br /> (0.04 cm0.4 mm <br />4.0e-4 m <br />) +
aquatic +  and terrestrial +