Part 7 - UNC Herbarium

POACEAE 860
Danthonia Augustin de Candolle (Oat-grass)
A genus of about 20 species, of North America, Europe, and the Americas, but the generic limits are unclear. References:
Darbyshire in FNA (2003a).
1 Lemma teeth (flanking the awn) 0.8-1.8 mm long, triangular, acuminate; glumes 8-13 mm long.............................. D. spicata
1 Lemma teeth (flanking the awn) (1.8-) 2.0-4.5 mm long, setaceous; glumes 9-19 mm long.
2 Lemma awn 4-10 mm long; glumes 9-13 mm long ...................................................................................... D. compressa
2 Lemma awn 11-18 mm long; glumes 11-19 mm long.
3 Sheaths villous; lemmas herbaceous in texture, villous on the back and sides; awn twisted at base several times,
forming an awn column 2.5-3 mm long ...................................................................................................... D. sericea
3 Sheaths glabrous; lemmas membranaceous in texture, villous only on the margins and towards the base; awn
twisted at base a single time, forming a loose awn column 0.5-1.5 mm long ................................................D. epilis
Danthonia compressa Austin ex Peck, Mountain Oat-grass. Mt, Pd (GA, NC, SC, VA), Cp (VA): grassy balds, thin soils
around rock outcrops, woodlands; common (uncommon in upper Piedmont only). June-August. Fairly widespread in e. North
America, primarily Appalachian, from s. Canada to SC and TN. [= RAB, C, F, FNA, G, HC, K, S, W]
Danthonia epilis Scribner, Bog Oat-grass. Cp (NC, SC, VA), Mt (GA, NC, VA?), Pd (NC): peaty bogs in the Coastal Plain
and Mountains, seeps around rock outcrops in the Piedmont and Mountains, granitic domes; rare (GA Special Concern, NC
Watch List, VA Watch List). April-June. The range is apparently bogs in pinelands from NJ to SC, in mountain bogs in NC, VA
(?), and GA, in seepage in the Cumberland Plateau and Blue Ridge of TN and AL. This taxon appears to be valid, with a distinct
range, habitat, and variety of morphologic characters separating it from D. sericea, but further study is needed. Material from the
mountains seems to differ from Coastal Plain material. RAB's description of the habitat as "dry woods, rare; pied. of N.C."
appears to be in error. Blomquist listed the taxon (as a variety) for bogs in the mountains of sw. NC. It has since been found in
bogs in the Sandhills region of NC and in seepage bogs in the adjacent Piedmont. [= F, HC, K, S; = D. sericea var. epilis
(Scribner) Blomquist – RAB, C; < D. sericea Nuttall – FNA]
Danthonia sericea Nuttall, Silky Oat-grass. Cp, Pd, Mt (GA, NC, SC, VA): dry woodlands, especially common in sandy
soils in the Coastal Plain, dry oak, oak-pine, and pine forests in the Piedmont and low Mountains; common (uncommon in the
Mountains). April-June. Primarily a Coastal Plain species northwards, ranging from e. MA south to FL and west to LA. [= F,
HC, K, S, W; = D. sericea var. sericea – RAB, C, G; < D. sericea – FNA]
Danthonia spicata (Linnaeus) Palisot de Beauvois ex Roemer & J.A. Schultes, Poverty Oat-grass. Mt, Pd (GA, NC, SC,
VA), Cp (NC, SC, VA): dry woodlands, rock outcrops, shale barrens; common. May-July. Newfoundland and British Columbia
south to FL and NM. [= RAB, C, FNA, G, HC, K, S, W; > D. spicata var. longipila Lamson-Scribner & Merrill – F; > D.
spicata var. spicata – F; < D. allenii Austin – F]
Deschampsia Palisot de Beauvois (Hairgrass)
A genus of about 40 species, north and south temperate. References: Tucker (1996)=Z.
1 Awn 2-3 mm long, straight or nearly so, scarcely (or not at all) exserted beyond the tips of the glumes; lemmas smooth; leaf
blades flat or folded at the midvein (V-shaped in cross-section); ligule 3-10 (-17) mm long; [section Deschampsia]...............
..............................................................................................................................................................D. cespitosa ssp. glauca
1 Awn 4-8 mm long, geniculate, exserted beyond the tips of the glumes; lemmas minutely scabrous; leaf blades involute,
appearing filiform (rounded in cross-section); ligule 0.5-3 (-5) mm long; [section Avenaria] ...........D. flexuosa var. flexuosa
Deschampsia cespitosa (Linnaeus) Palisot de Beauvois ssp. glauca (Hartman) Hartman, Tufted Hairgrass. Mt (NC, VA):
thin soil of rock outcrops or barrens over calcareous, mafic, and ultramafic rocks (such as serpentinized olivine, amphibolite,
limestone, and dolostone); rare (NC Rare, VA Rare). June-July. D. cespitosa is a complex species, with a complicated polyploid
and aneuploid series, variously subdivided (or not) by various taxonomists. As a whole, D. cespitosa is circumboreal, ranging
south in North America to NJ, sw. NC, WV, IL, MN, and AZ. Ssp. glauca is the most widespread American subspecies, and
extends the farthest south. Other subspecies occur farther north and in Eurasia. In our area, D. cespitosa is at its southern limit
and is a rare species limited to barrens and outcrops over mafic or ultramafic rocks. [= K; = D. caespitosa var. glauca (Hartman)
Lindman f. – RAB, F; < D. cespitosa – C, Z; < D. cespitosa var. cespitosa – G; < D. caespitosa var. caespitosa – HC; = D.
cespitosa ssp. cespitosa var. glauca (Hartman) Lindman f.; < Aira caespitosa Linnaeus – S; < D. caespitosa – W]
Deschampsia flexuosa (Linnaeus) Trinius var. flexuosa, Common Hairgrass, Wavy Hairgrass. Mt (GA, NC, SC, VA), Pd,
Cp (NC, VA): grassy balds, high elevation rocky summits, rocky or sandy woodlands; common (uncommon in Piedmont and
Coastal Plain) (SC Rare). April-August. Circumboreal, ranging south in North America to n. GA, OH, WI, and MN; disjunct in
AR and OK, and in Mexico. [= F, K; < D. flexuosa – RAB, C, G, HC, W, Z; < Aira flexuosa Linnaeus – S]
* Deschampsia elongata (Hooker) Munro, Slender Hairgrass. Cp (SC): waste areas near wool-combing mills; rare, perhaps
only a waif, native of w. North America. [= HC, K] {not keyed}