﻿Underwood : Selaginella rupestkis and its Allies 12D 



tional Herbarium are additional specimens collected on the Mex- 

 ican Boundary Survey. 



4. Selaginella arenaria sp. nov. 



Deeply rooting in sand with fine copious roots often 1 5-20 

 cm. long ; stems slender, branching, erect or ascending, densely 

 caespitose, 5-8 cm. high, emitting copious brown wiry roots a 

 little distance above the base ; leaves closely appressed, narrowly 

 lanceolate, 0.25 mm. wide, deeply channelled dorsally, terminated 

 by a spinulose white awn 0.35-0.50 mm. long; margins with 

 numerous short cilia ; spikes 2-3 cm. long, slender, sharply quad- 

 rangular, the bracts broadly lanceolate, spreading at maturity with 

 copious marginal cilia ( 1 5-20 on either side) ; microspores very 

 abundant throughout the length of the spike, globose-tetrahedral, 



Jan., 1 891 , 



36-39 p in diameter, bright yellow or pale orange. 



Growing in sand in open fields, Eustis, ] 

 Underwood; July, 1894, Nash, no. 1449. A fragmentary speci- 

 men of the same plant is in the Chapman Herbarium and bears 

 the note "Dry sand ridges, Gadsden Co., Florida, 1840." In 

 addition to the remarkable habit and habitat of this species it pro- 

 duces a great abundance of microspores unlike the other members 



of the rupestris group. 



In the Gray Herbarium there is a MS. description by Riddell 

 with meagre specimens of plants from w tern Loui ma and 

 Texas which resemble the above species in habit but have spito 

 scarcely more than one-third as long; they may prove a distinct 

 species, when Riddell's appropriate name should be taken up. To 

 the same species we should refer plants of Drummond's Texas 

 collection (Herb. Columbia and Herb. Kew), Riddell, no. 16 .11 

 Herb. Columbia and Reverchon's Texas Plants no. 1632, from 

 Burnet county, on granite rocks, though the latter specimens 

 show some slight variations particularly in the irregular ranking 

 of the leaves. 



5 / Selaginella rupincola sp. nov. 



Stems suberect, somewhat flexuous, 8-12 cm high, rooting 

 only from near the base, pinnately branching the secondary 

 branches mostlv very short; leaves channeled dorsally, closely 

 imbricate, spreading onlv near the growing tips <»t the stem, glau- 

 cous or cinereous green, tapering toward the apex and ending m a 



