Calamagrostis canadensis var. macouniana

(Vasey) Stebbins
Common names: Macoun's reedgrass
Treatment appears in FNA Volume 24. Treatment on page 728.

Culms 100-112 cm, not branching above the base, smooth beneath the panicles; nodes 5-7. Sheaths and collars smooth or slightly scabrous; ligules (2) 3-4 (5) mm; blades (10) 17-30 (33) cm long, 2-6 (8) mm wide, adaxial surfaces scabrous, sometimes with widely scattered long hairs, often glaucous. Panicles 14-17 (20) cm long, (2.5) 3 (4) cm wide, usually purplish; branches 4.8-6 (7) cm. Spikelets (2) 2.5-3 mm; rachilla prolongations about 0.5 mm, hairs 1.5-2 mm. Glumes rounded, smooth, or sometimes slightly scabrous distally, often only on the midvein, prickles straight, midveins not raised, lateral-veins obscure, apices acute; callus hairs 2-2.5 mm, nearly as long as the lemmas; lemmas 2-2.5 mm, 0-1 mm shorter than the glumes; awns 1.2-2 mm, attached to the lower 1/5-1/2 of the lemmas, not exserted, straight; anthers 1-2 mm. 2n = unknown.

Distribution

N.H., Va., Iowa, Nebr., S.Dak., Mass., Ohio, N.Dak., Mo., Minn., Mich., N.J., Wis., N.Y., Pa., Vt., Alta., Man., N.B., N.S., N.W.T., Ont., P.E.I., Que., Sask., Ky., Conn., Ill.

Discussion

Calamagrostis canadensis var. macouniana is common in marshes and mud flats. It ranges eastward from Saskatchewan to Prince Edward Island and Nova Scotia, and from North Dakota and Missouri to New Jersey and Virginia. According to C.L. Hitchcock (Hitchcock et al. 1969), it may extend as far west as Idaho.

Vernon Harms (pers. comm.) reports that in the southern grassland region of Saskatchewan, intermediates between Calamagrostis canadensis var. macouniana and var. canadensis appear to be more common than plants that fit var. macouniana well. Some specimens that seem nearest to var. macouniana stretch across southern Saskatchewan south of 51° N latitude, from the Cypress Hills in the west to the Souris Valley in the east. Harms' observations suggest that it may not be practical to recognize this variety.

Selected References

None.

Lower Taxa

None.

"decumbent" is not a number.

membranous +  and scarious +
with scattered hairs +  and smooth +
0.8 cm8 mm <br />0.008 m <br /> (?) +
0.1 cm1 mm <br />0.001 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
Kendrick L. Marr +, Richard J. Hebda +  and Craig W. Greenef +
(Vasey) Stebbins +
1 (?) +  and 3 (?) +
straight +
attached +
not exserted +  and lower +
indistinct +
1/5 +  and 1/2 +
0.12 cm1.2 mm <br />0.0012 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
keeled +  and rounded +
pseudopetiolate +  and branching +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
17 cm170 mm <br />0.17 m <br /> (30 cm300 mm <br />0.3 m <br />) +
not evident +
flat +  and involute +
2mm;6mm +
7 cm70 mm <br />0.07 m <br /> (?) +
appressed;more or less drooping +
spikelike +
(0.5)0.9-1.2(1.5) times as long as the lemmas +
0.2 cm2 mm <br />0.002 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
Macoun's reedgrass +
not branching +
ascending +  and erect +
100 cm1,000 mm <br />1 m <br /> (112 cm1,120 mm <br />1.12 m <br />) +
not woody +
N.H. +, Va. +, Iowa +, Nebr. +, S.Dak. +, Mass. +, Ohio +, N.Dak. +, Mo. +, Minn. +, Mich. +, N.J. +, Wis. +, N.Y. +, Pa. +, Vt. +, Alta. +, Man. +, N.B. +, N.S. +, N.W.T. +, Ont. +, P.E.I. +, Que. +, Sask. +, Ky. +, Conn. +  and Ill. +
1/4 +  and 1/3 +
liquid +, soft +  and hard +
capillary +
pistillate +  and staminate +
sometimes longer +
sterile +  and bisexual +
compressed +
reduced +
subtending +
rounded +
subequal +
membranous +
sparse +  and abundant +
uncinate +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
lanceolate +  and ovate +
0 cm0 mm <br />0 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
lacerate +
0.3 cm3 mm <br />0.003 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
membranous +
inconspicuous +
lanceolate +
8 (?) +  and 2 (?) +
concealed +  and prominent +
5 +  and 7 +
2 +  and 1 +
hairy +  and glabrous +
2-keeled +
14cm +  and 17cm +
spikelike +
2.5 cm25 mm <br />0.025 m <br /> (?) +
dry +  and fleshy +
1 +  and 60 +
compressed +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
1 (?) +  and 3 (?) +
simple +  and compound +
2 (?) +  and 3 (?) +
Calamagrostis anomala +
Calamagrostis canadensis var. macouniana +
Calamagrostis canadensis +
variety +
membranous +
parallel +  and converging +
obscure +  and prominent +
aquatic +  and terrestrial +