familyPoaceae
subfamilyPoaceae subfam. Pooideae
tribePoaceae tribe Stipeae
genus×achnella
species×achnella caduca

×achnella caduca

(Beal) Barkworth
Mary E. Barkworth
Common names: Dropawn
Treatment appears in FNA Volume 24. Treatment on page 169.
Please click on the illustration for a higher resolution version.
Illustrator: Cindy Roché

Copyright: Utah State University

Culms 50-90 cm, glabrous. Basal sheaths mostly glabrous, margins and throats usually ciliate; ligules 0.5-1.7 mm, truncate-rounded; blades 1-3.5 mm wide. Panicles 15-18 cm; branches ascending. Lower glumes 6-8.5 mm long, 1-1.6 mm wide; florets 4-5 mm; calluses about 0.7 mm; lemmas 7-veined, hairy, hairs 1-2 mm, apices awned; awns 9-16 mm, readily deciduous; paleas 2.5-3.3 mm, 2/3 - 3/4 the length of the lemmas, hairy; anthers 2, 1.7-2.3 mm, differing in length within the florets, indehiscent. 2n = 65.

Distribution

Alta., B.C., Man., N.W.T., Sask., Yukon, Mont., N.Dak., Nebr.

Discussion

×Achnella caduca is a sterile hybrid between Achnatherum hymenoides and Nassella viridula that occurs infrequently in Montana and Wyoming. It differs from Achnatherum hymenoides in its longer glumes and florets; from Nassella viridula in its more saccate glumes, longer lemma hairs, and well-developed palea; and from other hybrids involving Achnatherum hymenoides in its readily deciduous awn.

Selected References

None.

Lower Taxa

None.

"decumbent" is not a number."+timesthewidths" is not declared as a valid unit of measurement for this property.

... more about "×achnella caduca"
RDF feed
2n chromosome quantity
65 +
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 +
Anther dehiscence
indehiscent +
Anther development
developed +
Anther quantity
2 +
Anther some measurement
0.17 cm1.7 mm <br />0.0017 m <br /> (0.23 cm2.3 mm <br />0.0023 m <br />) +
Apex architecture or shape
awned +
Apex shape
narrowly acute +  and acuminate +
Arm cell presence
absent +
Auricle presence
absent +
Author
Mary E. Barkworth +
Authority
(Beal) Barkworth +
Awn architecture
twisted +
Awn atypical quantity
1 (?) +  and 3 (?) +
Awn orientation
arising +
Awn position
subterminal +  and eccentric +
Awn position or structure subtype
terminal +
Awn quantity
single +
Awn shape
not once-geniculate +
Awn some measurement
0.9 cm9 mm <br />0.009 m <br /> (1.6 cm16 mm <br />0.016 m <br />) +
Axillary panicle position
concealing +
Back shape
keeled +  and rounded +
Basal floret quantity
1 +  and 2 +
Basal margin architecture or pubescence or shape
ciliate +
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 arrangement
parallel +
Blade arrangement or course or shape
linear +
Blade prominence
not evident +
Blade shape
cross +, linear +  and narrowly lanceolate +
Blade width
0.1 cm1 mm <br />0.001 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
Branch orientation
ascending +
Branch quantity
many;1 +
Branch shape
spikelike +
Callus development
well-developed +
Callus pubescence
strigose +
Callus shape
blunt +
Callus some measurement
0.7 cm7 mm <br />0.007 m <br /> (?) +
Cleistogene presence
not absent +
Common name
Dropawn +
Culm architecture
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 orientation
erect +
Culm pubescence
glabrous +
Culm some measurement
50 cm500 mm <br />0.5 m <br /> (90 cm900 mm <br />0.9 m <br />) +
Culm texture
not woody +
Distal floret size
reduced +
Distribution
Alta. +, B.C. +, Man. +, N.W.T. +, Sask. +, Yukon +, Mont. +, N.Dak. +  and Nebr. +
Embryo quantity
0 +  and 1/3 +
Endosperm texture
liquid +, soft +  and hard +
Filament shape
capillary +
Floret architecture
pistillate +  and staminate +
Floret arrangement
adjacent +
Floret length or size
sometimes longer +
Floret pubescence
hairy +
Floret quantity
1 +
Floret reproduction
sexual +
Floret shape
compressed +  and terete +
Floret some measurement
4mm +  and 5mm +
Glume architecture or shape
awned +
Glume coloration
hyaline +
Glume fragility
pliable +
Glume length
1-10-veined +
Glume position
subtending +
Glume presence
absent +
Glume quantity
1/4 +
Glume shape
tapering +  and saccate-lanceolate +
Glume texture
membranous +
Hair length or size
longer +
Hair quantity
1 +
Hair shape
uncinate +
Hair some measurement
0.1 cm1 mm <br />0.001 m <br /> (0.2 cm2 mm <br />0.002 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 position or structure subtype
terminal +
Inflorescence size
reduced +
Internode architecture
solid +  and hollow +
Internode presence
absent +
Layer presence
absent +
Leaf arrangement
basally concentrated +  and evenly distributed +
Leaf blade length
40 cm400 mm <br />0.4 m <br /> (?) +
Leaf blade shape
Tapering (?) +
Leaf blade width
0.1 cm1 mm <br />0.001 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
Leaf margin arrangement
Overlapping (?) +
Lemma architecture
7-veined +
Lemma architecture or shape
not +  and awned +
Lemma pubescence
hairy +
Lemma shape
ovate +, rectangular +  and lanceolate +
Lemma texture
coriaceous +
Ligule architecture or pubescence or shape
ciliate +
Ligule presence
absent +
Ligule pubescence
glabrous +
Ligule shape
truncate-rounded +
Ligule some measurement
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.17 cm1.7 mm <br />0.0017 m <br />) +
Ligule texture
scarious +
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
lanceolate +
Lodicule texture
fleshy +  and membranous +
Lower glume length
0.6 cm6 mm <br />0.006 m <br /> (0.85 cm8.5 mm <br />0.0085 m <br />) +
Lower glume some measurement
0.6 cm6 mm <br />0.006 m <br /> (0.85 cm8.5 mm <br />0.0085 m <br />) +
Lower glume width
1mm +  and 1.6mm +
Margin architecture or pubescence or shape
ciliate +
Midrib architecture
simple +
Node prominence
concealed +  and prominent +
Number of lower taxa
0 +
Other quantity
2 +  and 1 +
Ovary presence
absent +
Ovary pubescence
pubescent +  and glabrous +
Palea development
well-developed +
Palea presence
absent +
Palea quantity
2/3 +  and 3/4 +
Palea shape
keeled +
Palea size
reduced +
Palea some measurement
0.25 cm2.5 mm <br />0.0025 m <br /> (0.33 cm3.3 mm <br />0.0033 m <br />) +
Panicle development
developing +
Panicle some measurement
15 cm150 mm <br />0.15 m <br /> (18 cm180 mm <br />0.18 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 +
Sheath pubescence
glabrous +
Source xml
https://bibilujan@bitbucket.org/aafc-mbb/fna-fine-grained-xml.git/src/84153f6d59a0a91d69695978a64cee7560374f8e/V24/V24 233.xml +
Spike architecture
ebracteate +
Spikelet arrangement
mixed +
Spikelet fixation
attached +
Spikelet quantity
1 +  and 60 +
Spikelet reproduction
unisexual +  and bisexual +
Spikelet shape
laterally compressed +  and terete +
Spikelet some measurement
0.6 cm6 mm <br />0.006 m <br /> (0.85 cm8.5 mm <br />0.0085 m <br />) +
Stamen quantity
1 +  and 3 +
Starch-grain architecture
simple +  and compound +
Style-branch atypical quantity
4 +  and 1 +
Style-branch quantity
2 (?) +  and 3 (?) +
Style quantity
2 +
Subsidiary-cell architecture
parallel-sided +
Synonyms
Gramineae +
Taxon family
Poaceae +
Taxon name
×achnella caduca +
Taxon parent
×achnella +
Taxon rank
species +
Terminal floret reproduction
sexual +
Tissue coloration
hyaline +
Tissue texture
membranous +
Upper glume some measurement
0.65 cm6.5 mm <br />0.0065 m <br /> (0.75 cm7.5 mm <br />0.0075 m <br />) +
Upper glume width
slightly narrower +
Vein presence
absent +
Vein prominence
inconspicuous +
Vein quantity
2 (?) +
Vein size
major +
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
12 +, 11 +, 10 +, 8 +  and 7 +