Calamagrostis lapponica
Calamagrostis porteri
calamagrostide de lapponie, Lapland reedgrass
Porter's reedgrass
(12)35-50(90) cm, unbranched, smooth beneath the panicles;
nodes 1-2(3).
(60)75-120 cm, unbranched, slightly scabrous;
nodes 2-4(5).
and collars usually smooth, rarely with short hairs;
ligules (0.5)2-4(5.5) mm, usually truncate, entire;
blades (4)8-18(26) cm long, (1.5)2-3.5(4) mm wide, flat to involute, abaxial surfaces usually smooth, rarely slightly scabrous, adaxial surfaces usually smooth or scabrous, rarely sparsely hairy.
smooth or slightly scabrous;
collars smooth or hairy;
ligules (1)2-5(6) mm, truncate to obtuse, entire or lacerate;
blades 8-40 cm long, (2)3-8(12) mm wide, flat, abaxial surfaces smooth or scabrous, adaxial surfaces smooth or slightly scabrous, occasionally with hairs.
(4)8-11(16) cm long, (0.7)1-2(2.8) cm wide, mostly erect, loosely contracted, purple;
branches (2.1)2.5-3.5(5.4) cm, smooth or slightly scabrous, sometimes spikelet-bearing to the base, sometimes only on the distal 2/3.
(5)10-18(22) cm long, 0.8-3(7) cm wide, contracted to open, often slightly nodding, sometimes erect, green to pale purple;
branches (1.5)2-7(7.5) cm, scabrous, usually spikelet-bearing on the distal 1/2 - 2/3, sometimes to the base.
(3.5)4-5(5.5) mm;
rachilla prolongations 0.4-1 mm, hairs 1.8-3 mm.
4-5(6) mm;
rachilla prolongations 0.5-1 mm, hairs 1.5-2(3.5) mm.
usually more than 3 times as long as wide, rounded to slightly keeled, usually purple for most of their length and smooth, keels rarely slightly scabrous, lateral veins obscure, apices acute to acuminate;
callus hairs (2)3-3.5(4.7) mm, (0.6)0.8-1(1.2) times as long as the lemmas, abundant;
lemmas (2.5)3-4(5) mm, 0.3-1.5 (2.3) mm shorter than the glumes;
awns 1.5-3 mm, attached to the lower 1/10 – 2/5 of the lemmas, usually not exserted, usually slender and similar to the callus hairs, sometimes stouter, straight to somewhat bent;
anthers (1.1)1.3-1.7(2) mm, usually poorly developed, sterile.
rounded to slightly keeled, keels scabrous towards the apices, lateral veins obscure to slightly prominent, not raised, apices acute to acuminate;
callus hairs 1.5-2(3) mm, 0.4-0.7 times as long as the lemmas, sparse;
lemmas 3-4.5 mm, 0.5-1.5(2) mm shorter than the glumes;
awns 3-4(4.5) mm, attached to the lower 1/10 – 3/10 of the lemmas, exserted, stout, easily distinguished from the callus hairs, strongly bent;
anthers 2-2.5 mm.
= 28, 42-112, 140.
= 56, 84-+104.
Calamagrostis lapponica
Calamagrostis porteri
Calamagrostis lapponica grows in northern and alpine tundra, particularly on ridgecrests and upper slopes, often with low shrubs including heathers, dwarf willows, and dwarf birch, usually on well-drained and coarse-textured (sand and gravel) soils, infrequently in meadows beside streams and lakeshores, very rarely in standing water, at 30-2300 m. It is circumboreal and circumpolar, ranging from Alaska to western Greeneland and Labrador, including the islands of the high arctic, south into the mountains of northern British Columbia and the west-central Rocky Mountains of Alberta. In Europe it extends south to about 60° N latitude, and in Asia south to North Korea.
Calamagrostis lapponica is sometimes easily confused with C. stricta (see next), but the two grow in different habitats. In addition, the glumes of C. lapponica have a smoother, more glossy appearance than those of C. stricta and are typically purple for most of their length, including the apices; the glumes of C. stricta are generally brown at the apices. A specimen from Nakat Inlet, Alaska (ALA #V116195, J. DeLapp and M. Duffy 93-339) appears to be C. lapponica, although it is in a very different habitat and at an unusually low elevation for the species.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Calamagrostis porteri grows in dry chestnut/oak forests, often on rocky ridgetops, piedmont bluffs, and slopes, at (100)600-1300 m. It is now restricted to the northeastern and central United States. Historically, its range extended from Missouri and Arkansas east to New York and Alabama. Flowering appears to be a response to disturbance; plants in undisturbed habitats remain vegetative and may go unnoticed. Thus the species may be more widespread and abundant than reported.
Calamagrostis porteri and C. rubescens (see next) appear to be closely related. They may be part of the general phenomenon of eastern and western vicariants. The apparently sterile C. perplexa (p. 726) is intermediate between C. porteri and C. canadensis (Greene 1980).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Leaf blades glaucous on both surfaces; leaf collars glabrous | subsp. insperata |
1. Leaf blades light green and glaucous on the adaxial surfaces, darker green on the abaxial surfaces; leaf collars usually with prominent tufts of hair, rarely glabrous | subsp. porteri |
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