448 BiCKNELL : Ferns and floavering plants of Nantucket 



by reduced examples from Torbay (C. D. Hozve & W. F. Lang", 

 ij6j^ August 21-26, T901, ledges of damp sea-cliffs). 



In the herbarium of the New York Botanical Garden are speci- 

 mens closely similar to the Maine plant collected by Professor B, 

 Jonsson in Scandinavia and labeled P. avicidare van maxivuun and 

 from Geneva, ex herb. Meisner, labeled P. aviadare var. vegetmn 

 Ledeb. This latter determination may be correct, but var. vegetinn, 

 as It has been interpreted, is a very different plant, the P. moiispeli- 

 ense Thieb. of Persoon*s Synopsis, which represents a parallel devel- 

 opment along the collateral P, aviadare line. The plant is prob- 



latifoliian 



204). 



The opposite extreme of P. neglectiini from this larger form is 

 seen in a delicate, slender-stemmed and widely branched form 

 which grew flatly prostrate on damp sand about ponds on the 

 south shore of Nantucket. The pale yellowish-green linear leaves 

 are very small and, excepting the midvein, nerveless or nearly so, 

 0.5-1.5 cm. long, 1-2 mm. wide, obtuse or acutish ; ochreae 

 rather short, the divisions often weakly scarious ; flowers very 

 small; achene exserted at tip, 1.5-2 mm. long, i. 25-1. 50 mm. 

 wide, plumper than in the typical form and more abruptly con- 

 tracted at the base and blunter at the tip. 



There would seem to be little doubt from Koch's description 

 (Linnaea 22 : 204) that this plant may be referred to his P. avicu- 

 lare tj temnssiimim. The similarity of the flowering branches oi 

 the plant to those of the erect P. temte Michx., which is remarked 

 by Koch, is obvious in the Nantucket specimens. 



Another very distinct-appearing form found sparingly on Nan- 

 tucket, perhaps not to be referred to this species, is rather dark 

 green, often becoming black when dry, erect or erect-ascending, 

 2-3.5 d"^- ^^gh, with very slender and fragile, often zigzag, stems 

 and branches, the leaves relatively thin, narrowly lanceolate and 

 very acute, tapering to base and apex ^nd distinctly slender-peti- 

 oled ; the ochreae are large and funnelform and show an extreme 

 development of the stiffly lanceolate final divisions. In this form 

 the inflorescence is not in the least spicate, its very small flowers 

 being rather distant and axillary and the leaves scarcely, if at all, 

 reduced in size towards the tips of the branches. Some speci- 



P. 



erecttim. 



