Bicknell: Ferns and flowering plants of Nantucket 447 



these forms, for the present so treated, will be found to be essen- 

 tially distuict plants. 



The species itself has been so obscurely known and little rec- 

 ognized that detailed descriptions may be useful : 



What may be understood as being the typical plant is dull 

 light-green in color, erect, ascending, or prostrate, rather stiff, 

 widely slender-branched from the base ; internodes rather short, 

 often zigzag, striate, usually minutely roughened; leaves firm, 

 elliptic to narrowly elliptic-lanceolate, acute, narrowed to the base, 

 sessile or very short-petioled, prominently veined on the lower 

 surface and somewhat scurfy-punctate, the margins often distinctly 

 crisped or cartilaginous-roughened, and revolute when dry; leaves 

 of the branchlets gradually reduced upwards and becoming very^ 

 small, linear-lanceolate and acute to linear and obtuse; ochreae 

 silvery brown when young and narrowly lanceolate-attenuate, 

 finally lacerate into narrow stiffly ascending bristleform divisions, 

 or sometimes weak and flexuous, the base mostly funnelform, be- 

 coming blackish ; terminal inflorescence appearing more or less 

 subspicate, the flowers with very short pedicels, mostly sessile or 

 two together; mature flowering calyx 2—3 mm. long, often strongly 

 venose, the margins commonly purplish red ; achene mostly ex- 

 serted at tip, usually somewhat unevenly trigonous with the faces 

 nearly plane, commonly rather smaller than in P. aviculare, less 

 strongly rugulose and lighter and more reddish brown in color, 

 often more abrupt at base and apiculate. 



A broader-leaved, often larger form bears diffuse, decompound, 

 widely ascending branches, sometimes 7.5 dm. in length, the ulti- 

 mate branches slender and flexuous ; longer internodes 5 cm. long, 

 the uppermost very short ; larger leaves sometimes obovoid- 

 oblong, becoming 3.5 cm. long and 1.2 cm. wide, the margins 

 firmly crenulate ; ochreae relatively short and not usually stiffly 

 bristly-lacerate ; flowers distinctly pedicelled, large, becoming 3- 

 3.5 mm. long, the bright carmine, somewhat petaliferous segments 

 conceahng the tip of the achene; achene large, 2.5-3 mm. long, 

 1.5-2 mm. wide, evenly trigonous with deeply concave faces, 

 red-brown, dull but shining on the angles, strongly rugulose and 

 apiculate. 



The examples here described were collected at York Harbor, 

 Maine, on August 15, 1893, and August 19, 1S94, and grew in 

 stony places back of the beaches. The same plant although less 

 strongly developed is common on Mt. Desert, Maine, where I 

 collected it in 1895, growing in the same situations as at York 

 Harbor. That it occurs as far east as Newfoundland is attested 



