familyPoaceae
subfamilyPoaceae subfam. Pooideae
tribePoaceae tribe Stipeae
genusAchnatherum
speciesAchnatherum occidentale
subspeciesAchnatherum occidentale subsp. pubescens

Achnatherum occidentale subsp. pubescens

(Vasey)
Mary E. Barkworth
Common names: Common western needlegrass
Endemic
Synonyms: Stipa occidentalis var. pubescens Stipa lemmonii var. pubescens Stipa elmeri
Treatment appears in FNA Volume 24. Treatment on page 123.
Please click on the illustration for a higher resolution version.
Illustrator: Cindy Roché

Copyright: Utah State University

Culms 32-120 cm tall, 0.8-1.3 (2) mm thick, basal internodes puberulent to pubescent. Basal sheaths usually pubescent, sometimes densely pubescent, occasionally glabrous; collars often with tufts of hair at the sides; blades 1-3 mm wide, adaxial surfaces pubescent to pilose. Panicles 10-30 cm; longest branches 2-7 cm. Glumes usually green; lemmas with apical pubescence similar in length to the basal awn pubescence; awns 24-50 mm, pilose on the first 2 segments, with hairs gradually becoming shorter distally, terminal segment scabrous or glabrous. 2n = 36.

Discussion

Achnatherum occidentale subsp. pubescens grows from Washington to California and eastward to Wyoming, at 1300-4700 m. It is the most widespread and variable subspecies of A. occidentale, intergrading with subsp. californicum, A. nelsonii, and A. lettermanii. It differs from the latter two in its shorter paleas and its pilose awns.

Selected References

None.

Lower Taxa

None.

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

... more about "Achnatherum occidentale subsp. pubescens"
RDF feed
2n chromosome quantity
36 +
Abaxial ligule presence
absent +
Abaxial ligule quantity
common +
Adaxial cell presence
absent +
Adaxial cell shape
bulliform +
Adaxial ligule architecture or pubescence or shape
ciliate +
Adaxial ligule presence
absent +
Adaxial ligule texture
membranous +  and scarious +
Adaxial surface pubescence
pubescent +  and pilose +
Anther dehiscence
dehiscent +
Anther quantity
3 +
Anther shape
not penicillate +
Anther some measurement
0.25 cm2.5 mm <br />0.0025 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
Apex architecture or shape
awned +, bifid +, bilobed +  and entire +
Apex fragility
pliable +
Apex shape
rounded +
Apical hair some measurement
0 cm0 mm <br />0 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
Arm cell presence
absent +
Auricle presence
absent +
Author
Mary E. Barkworth +
Authority
(Vasey) +
Awn architecture
twisted +
Awn atypical quantity
1 (?) +  and 3 (?) +
Awn course
flexuous +
Awn orientation
arising +
Awn position
subterminal +  and eccentric +
Awn position or structure subtype
terminal +
Awn pubescence
pilose +
Awn quantity
single +
Awn relief
usually scabrous +  and scabridulous +
Awn shape
not once-geniculate +
Awn some measurement
2.4 cm24 mm <br />0.024 m <br /> (5 cm50 mm <br />0.05 m <br />) +
Axillary panicle position
concealing +
Back shape
keeled +  and rounded +
Basal floret quantity
1 +  and 2 +
Basal sheath pubescence
glabrous +  and pubescent +
Base architecture
pseudopetiolate +  and branching +
Base arrangement
close +
Base fusion
fused +
Base position
intravaginal +, extravaginal +, branching +  and basal +
Base size
swelling +
Base texture
hard +
Base width
thick +
Blade architecture or arrangement
lax +
Blade arrangement
parallel +
Blade arrangement or course or shape
linear +
Blade course
straight +
Blade diameter
0.01 cm0.1 mm <br />1.0e-4 m <br /> (0.08 cm0.8 mm <br />8.0e-4 m <br />) +
Blade prominence
not evident +
Blade shape
convolute +  and flat +
Blade width
0.1 cm1 mm <br />0.001 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
Branch course
straight +
Branch fixation or orientation
appressed +
Branch fusion
fused +
Branch quantity
many;1 +
Branch shape
spikelike +
Callus development
well-developed +
Callus pubescence
strigose +
Callus shape
sharp +
Callus some measurement
0.08 cm0.8 mm <br />8.0e-4 m <br /> (0.12 cm1.2 mm <br />0.0012 m <br />) +
Cleistogene presence
not absent +
Common name
Common western needlegrass +
Culm architecture
branching +  and not branching +
Culm architecture or arrangement or growth form
solitary +
Culm duration
perennial +  and annual +
Culm growth form
climbing +
Culm growth form or location
floating +
Culm height
32 cm320 mm <br />0.32 m <br /> (120 cm1,200 mm <br />1.2 m <br />) +
Culm orientation
erect +
Culm position
intravaginal +  and basal +
Culm some measurement
10 cm100 mm <br />0.1 m <br /> (250 cm2,500 mm <br />2.5 m <br />) +
Culm texture
not woody +
Culm thickness
0.08 cm0.8 mm <br />8.0e-4 m <br /> (0.13 cm1.3 mm <br />0.0013 m <br />) +
Distal floret size
reduced +
Distribution
Utah +, Wash. +, Colo. +, Mont. +, Alta. +, B.C. +, Idaho +, Calif. +, Wyo. +, Ariz. +, Nev. +  and Oreg. +
Embryo quantity
1/5 +  and 1/3 +
Endosperm texture
liquid +, soft +  and hard +
Filament shape
capillary +
Floret architecture
pistillate +  and staminate +
Floret arrangement
adjacent +
Floret length
0.55 cm5.5 mm <br />0.0055 m <br /> (0.75 cm7.5 mm <br />0.0075 m <br />) +
Floret length or size
sometimes longer +
Floret pubescence
hairy +
Floret quantity
1 +
Floret reproduction
sexual +
Floret shape
terete +  and fusiform +
Glume architecture
1-7-veined +
Glume architecture or shape
awned +
Glume coloration
green +
Glume fragility
pliable +
Glume length
9mm +  and 15mm +
Glume position
subtending +
Glume presence
absent +
Glume quantity
1/4 +
Glume shape
obtuse +, acute +  and acuminate +
Glume size
subequal +
Glume texture
membranous +
Glume width
0.6mm +  and 0.9mm +
Hair arrangement
divergent +  and distributed +
Hair height or length or size
shorter +
Hair length or size
longer +
Hair shape
uncinate +
Hair some measurement
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
Hilum arrangement or course or shape
linear +
Hilum coloration or relief
punctate +
Hilum shape
Ovate (?) +
Illustration
Present +
Illustration copyright
Utah State University +
Illustrator
Cindy Roché +
Inflorescence architecture
compound +
Inflorescence condition or size
contracted +
Inflorescence position or structure subtype
terminal +
Inflorescence quantity
2 +
Inflorescence size
reduced +
Internode architecture
solid +  and hollow +
Internode presence
absent +
Internode pubescence
puberulent +  and densely pubescent +
Layer presence
absent +
Leaf arrangement
basally concentrated +  and evenly distributed +
Leaf arrangement or density
concentrated +
Leaf margin arrangement
Overlapping (?) +
Lemma architecture
3-5-veined +
Lemma architecture or pubescence or relief
smooth +
Lemma architecture or shape
not +  and awned +
Lemma body some measurement
0 cm0 mm <br />0 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
Lemma length or size
longer +
Lemma margin arrangement
overlapping +
Lemma pubescence
glabrous +  and hairy +
Lemma quantity
1/3 +
Lemma shape
ovate +, rectangular +  and lanceolate +
Lemma texture
stiffly membranous +  and coriaceous +
Ligule architecture or pubescence or shape
ciliate +
Ligule coloration
hyaline +
Ligule presence
absent +
Ligule pubescence
pubescent +  and glabrous +
Ligule some measurement
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
Ligule texture
membranous +
Lobe some measurement
? (?) +
Lobe texture
membranous +
Lodicule architecture
veined +
Lodicule architecture or pubescence or shape
ciliate +
Lodicule architecture or shape
truncate +
Lodicule prominence
inconspicuous +
Lodicule quantity
3 +  and 2 +
Lodicule shape
not lobed +
Lodicule texture
membranous +
Longest branch some measurement
2 cm20 mm <br />0.02 m <br /> (7 cm70 mm <br />0.07 m <br />) +
Margin architecture or pubescence or shape
ciliate +
Midrib architecture
simple +
Node prominence
concealed +  and prominent +
Node pubescence
pubescent +  and glabrous +
Node quantity
2 +  and 4 +
Number of lower taxa
0 +
Other quantity
2 +  and 1 +
Ovary presence
absent +
Ovary pubescence
pubescent +  and glabrous +
Palea architecture
2-veined +
Palea development
well-developed +
Palea presence
absent +
Palea pubescence
pubescent +
Palea quantity
2/5 +  and 3/5 +
Palea shape
not keeled +
Palea size
reduced +
Palea some measurement
0.22 cm2.2 mm <br />0.0022 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
Panicle development
developing +
Panicle length
5cm +  and 30cm +
Panicle some measurement
10 cm100 mm <br />0.1 m <br /> (30 cm300 mm <br />0.3 m <br />) +
Panicle width
0.5 cm5 mm <br />0.005 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
Papilla presence
absent +
Pericarp arrangement
separating +
Pericarp condition or texture
dry +
Pericarp texture
dry +  and fleshy +
Pericarp width
thin +
Pseudopetiole presence
absent +
Rachilla length
not prolonged +
Rachis prominence
evident +
Reference
None +
Sheath architecture
open +
Sheath condition
closed +
Sheath length
full +
Source xml
https://bibilujan@bitbucket.org/aafc-mbb/fna-fine-grained-xml.git/src/84153f6d59a0a91d69695978a64cee7560374f8e/V24/V24 171.xml +
Special status
Endemic +
Spike architecture
ebracteate +
Spikelet arrangement
mixed +
Spikelet fixation
attached +
Spikelet fixation or orientation
appressed +
Spikelet quantity
1 +  and 60 +
Spikelet reproduction
unisexual +  and bisexual +
Spikelet shape
laterally compressed +  and terete +
Stamen quantity
1 +  and 3 +
Starch-grain architecture
simple +  and compound +
Style-branch atypical quantity
4 +  and 1 +
Style-branch quantity
2 (?) +
Style quantity
2 +
Subsidiary-cell architecture
parallel-sided +
Synonyms
Stipa occidentalis var. pubescens +, Stipa lemmonii var. pubescens +  and Stipa elmeri +
Taxon family
Poaceae +
Taxon name
Achnatherum occidentale subsp. pubescens +
Taxon parent
Achnatherum occidentale +
Taxon rank
subspecies +
Terminal awn quantity
single +
Terminal floret reproduction
sexual +
Tip pubescence
glabrous +
Tissue coloration
hyaline +
Tissue texture
membranous +
Upper lemma quantity
74 +
Vein presence
absent +
Vein prominence
inconspicuous +
Vein quantity
2 (?) +
Vein size
major +
Vein some measurement
0.1 cm1 mm <br />0.001 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
Volume
Volume 24 +
Whole organism architecture
not rhizomatous +
Whole organism arrangement or pubescence
tufted +
Whole organism duration
perennial +
Whole organism growth form
plant +  and cespitose +
Whole organism growth form or habitat
aquatic +  and terrestrial +
X chromosome quantity
11 +  and 10 +