56 CONTRIBUTIONS PROM THE NATIONAL HERBARIUM. 



8. AGROSTIS L. 



AgrostisL. Sp. PI. 61. 1753. 



Spikelets 1-floworcd; raehilla articulated above the glumes, not produced beyond 

 the floret; glumes 2, Bubequal, usually exceeding the floret; lemma less firm in 

 texture than the glumes, awnless, or with a slender dorsal awn; palea hyaline, shorter 

 than the lemma, or wanting. Mostly perennial grasses with small spikelets in open, 

 usually diffuse panicles. 



Palea conspicuous, about one-half the length of the lemma 1. A. alba. 



Palea minute or wanting. 



Panicle diffuse, the branches capillary, scabrous 2. A. hyemalis. 



Panicle usually contracted, or if spreading the branches glabrous. 



Spikelets awnless 3. A. exarata, 



Spikelets awned. 



Awn straight, included 4. A. melakuca. 



Awn geniculate, exserted 5. A. borealis. 



1. Agrostis alba L. Sp. PI. 63. 1753. Redtop. 

 An erect, glabrous perennial 30 to 80 cm. high, sometimes decumbent and stolonif- 



erous at the base, with numerous plane scabrous leaves and contracted or open green 

 or purplish panicles 5 to 15 cm. long, the branches ascending or erect; ligule 6 mm. 

 long or less; spikelets 2 to 2.5 mm. long, the glumes subequal, acute, scabrous on 

 the keel; lemmas obtuse or acute, awnless. 



Kodiak Island and Cook Inlet. Extensively introduced throughout North America 

 and perhaps native northward. 



Specimens examineu: Kodiak, Georgeaon 1 in 1898, an old specimen doubtfully 

 referred to this species; Homer, Piper 4619. 



2. Agrostis hyemalis (Walt.) 15. S. P. Prel. Cat. N. Y. 68. 1888. 

 Cornucojiiae. In/eiiialis Walt. Kl. Carol. 73. 1788. 



Agrostis scabra Willd. Sp. PI. 1: 370. 1798. 



A slender, tufted, glabrous perennial 30 to (30 cm. high, with ample, spreading, 

 capillary, usually purplish panicles, often 40 cm. long, with strongly scabrous branches 

 and numerous small awnless spikelets; spikelets 1.5 to 2 mm. long; glumes subequal, 

 acute, scabrous on the keels. 



The Shumagin Islands, Prince William Sound, and the valley of the Yukon to 

 Newfoundland and southward. 



Specimens examined: Apollo, Piper 4032, 4030; Yukon River, Funston 148; 

 Kenai, Piper 4633, 4635; Nagai island, Harrington in 1871; Homer, Evans 497, Piper 

 4634; Valdez, Piper 4631. 



An exceedingly variable species which presents many interesting forms, of which 

 the extremes in habit and vegetative characters are very distinct from each other, 

 but on account of the many intergrading forms can not be readily separated. 



2a. Agrostis hyemalis nutkaensis (Kunth). 



Trichodium album Presl, Pel. Haenk. 1: 244. 1830." 



Agrostis nutkaensis Kunth, Enum. PI. 1: 222. 1833. 



Slender, 15 to 40 cm. high, with comparatively small, pale or rarely purplish pani- 

 cles 4 to 10 cm. long; spikelets as in the species. 



Aleutian Islands to southeastern Alaska and southward. 



Specimens examined: Unalaska, Piper 4225; Shumagin Islands, Popof, Trelease 6c 

 Saunders, 2902, 2904, 2905, Saunders & Kincaid in 1899; Yes Bay, Behm ('anal, Howell 

 1711; Kodiak, Trelease & Saunders 2901, Piper 41524. 



A subspecies distinguished from the species only by its smaller size and smaller, 

 more or Jess contracted, and usually pale panicles. 



a See also Scribn. Rep. Mo. Bot. Gard. 10: 54. pi. 34- 1899. 



