Calamagrostis porteri subsp. porteri

Treatment appears in FNA Volume 24. Treatment on page 723.

Culms (60) 75-100 cm. Sheaths smooth or slightly scabrous; collars usually with prominent tufts of hair, rarely glabrous; ligules (1) 2-5 (6) mm; blades 8-40 cm long, (2) 3-6 (8) mm wide, abaxial surfaces darker green than the adaxial surfaces, adaxial surfaces light green, glaucous. Panicles (5) 10-12 (15) cm long, 0.8-3 (7) cm wide; branches (1.5) 2-5 cm. Spikelets 4-5 mm; rachilla prolongations with 1.5-2 (3.5) mm hairs. Callus hairs 1.5-2 mm, 0.4-0.6 times as long as the lemmas; lemmas 3.5-4.5 mm, 0.5-1.5 mm shorter than the glumes; awns 3-4 (4.5) mm, attached to the lower 1/10 – 1/5 of the lemmas; anthers about 2 mm. 2n = 84-±104.

Discussion

Calamagrostis porteri subsp. porteri grows from New York to Virginia, Tennessee, and Kentucky. One specimen from Claiborne County, Tennessee, lacks hairs around the collar, but the leaves are glaucous on both surfaces. There are other specimens from this county that have hairy collars.

Calamagrostis porteri subsp. porteri appears to form hybrids with the nearly sympatric C. canadensis (p. 726) in rocky wooded sites in central Virginia. These putative hybrids have hairy collars, relatively long callus hairs, and short awns.

Selected References

None.

Lower Taxa

None.

"decumbent" is not a number.

membranous +  and scarious +
2 cm20 mm <br />0.02 m <br /> (?) +
Acute (?) +  and Acuminate (?) +
Kendrick L. Marr +, Richard J. Hebda +  and Craig W. Greenef +
A. Gray +
1 (?) +  and 3 (?) +
4.5 cm45 mm <br />0.045 m <br /> (?) +
straight +
attached +
distinguished +
1/10 +  and 1/5 +
0.3 cm3 mm <br />0.003 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
keeled +  and rounded +
pseudopetiolate +  and branching +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
8 cm80 mm <br />0.08 m <br /> (40 cm400 mm <br />0.4 m <br />) +
not evident +
flat +  and involute +
3mm;6mm +
1.5 cm15 mm <br />0.015 m <br /> (?) +
appressed;more or less drooping +
spikelike +
0.4-0.6 times as long as the lemmas +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
ascending +  and erect +
75 cm750 mm <br />0.75 m <br /> (100 cm1,000 mm <br />1 m <br />) +
not woody +
Md. +, W.Va. +, Pa. +, Ohio +, Mo. +, N.C. +, Tenn. +, Va. +, N.Y. +, Ark. +, Ill. +, Ga. +, Ind. +  and Ky. +
1/4 +  and 1/3 +
liquid +, soft +  and hard +
capillary +
pistillate +  and staminate +
sometimes longer +
sterile +  and bisexual +
compressed +
reduced +
subtending +
rounded +  and slightly keeled +
subequal +
membranous +
3.5 cm35 mm <br />0.035 m <br /> (?) +
sparse +  and abundant +
uncinate +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
not raised +, obscure +  and slightly prominent +
lanceolate +  and ovate +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
truncate +  and obtuse entire or lacerate +
0.2 cm2 mm <br />0.002 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
membranous +
inconspicuous +
lanceolate +
concealed +  and prominent +
2 +  and 4 +
2 +  and 1 +
hairy +  and glabrous +
2-keeled +
green +  and pale-purple +
10cm +  and 12cm +
erect +  and nodding +
spikelike +
0.8 cm8 mm <br />0.008 m <br /> (3 cm30 mm <br />0.03 m <br />) +
dry +  and fleshy +
1 +  and 60 +
compressed +
0.4 cm4 mm <br />0.004 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
1 (?) +  and 3 (?) +
simple +  and compound +
2 (?) +  and 3 (?) +
Gramineae +
Calamagrostis porteri subsp. porteri +
Calamagrostis porteri +
subspecies +
membranous +
parallel +  and converging +
obscure +  and prominent +
plant +  and cespitose +
aquatic +  and terrestrial +
0.5mm +  and 1mm +