8 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. '/2 



mex'icana Maxon, all of which are much larger plants of essentially 

 erect growth and differ, besides, in numerous technical characters. 

 The very slender, rigid branches and spaced, half-appressed, strongly 

 setigerous leaves give the plant a scant, harsh aspect, which has sug- 

 gested the specific name. 



SELAGINELLA LEUCOBRYOIDES Maxon, sp. nov. 

 (PI. 5) 



Plants very closely prostrate, the stems short-creeping, i to 2 cm. 

 long or less, closely aggregate, simply pinnate, the divisions thick, 

 strongly cespitose, erect, only 2 to 7 mm. long, or the terminal ones 

 bearing erect elongate spikes, all the parts densely leafy. Leaves 

 crowded, closely appressed-imbricate, mostly incurved, glaucous, 

 linear-subulate, uniform as to shape, variable in size, the basal ones 

 2.8 to 3.25 mm. long (seta included), 0.44 to 0.53 mm. broad, the 

 upper ones mostly 2 to 2.8 mm. long (seta included) , 0.42 to 0.5 mm. 

 broad, all short-setigerous at the acutish whitish thickened apex (the 

 seta stout, white, not translucent, subflexuous, 0.125 to 0.28 mm, long, 

 strongly scabrous, often reflexed), ciliate (the cilia 8 to 16 on each 

 side, those of the basal half spreading, 0.6 to 0.13 mm. long, the 

 upper ones shorter, distant, ascending), thick, rigidly herbaceous, 

 flat or broadly concave above, convex beneath (strongly so toward 

 the apex), the median groove deep, broad, nearly percurrent. Spikes 

 relatively numerous, aggregate, 5 to 10 mm. long, about 1.5 mm, 

 thick, erect, nearly straight ; sporophylls rigidly appressed-imbricate, 

 cieeply concave, narrowly to broadly deltoid-ovate, evenly long- 

 acuminate, about 2 mm. long, 0.8 to i mm. broad, short-setigerous 

 (the seta white, rigid, pointed, subentire, about 0.15 mm. long or 

 less), ciliate-serrulate ; cilia or teeth 20 to 25 on each side, the basal 

 cilia not more than 0.046 mm. long, pungent, oblique, passing grad- 

 ually into oblique hyaline teeth toward the apex. Megasporangia 

 few, basal ; megaspores subglobose, bright yellow, about 0.47 mm. in 

 diameter, the outer face obscurely reticulate, the commissural faces 

 manifestly so; commissural costae short, elevated. Microsporangia 

 numerous ; microspores orange, about 0.039 mm. in diameter. 



Type in the U. S. National Herbarium, No. 982453, collected at 

 Bonanza Mine, Providence Mountains, southeastern California, alt. 

 840 meters, in crevices, rocky mountain side, March 30, 1920, 

 by P. A. Munz and R. D. Harwood (No. 3789) . The following addi- 

 tional material is at hand : 



