1 42 OUR NATIVE FERNS AND THEIR ALLIES. 



ana (Drutnm<md)\ Aspalaga, Florida (Citrtiss, No. 3799 in 

 part). 



** Stems densely tufted, rolling into a nest-like ball when dry ; 

 roots confined to base of stems. 



7. S. lepidophylla Spring. Stems 2' 4' long, densely 

 tufted, pinnately branched to the base, the pinnae ascending, 

 sub-flabellately compound ; leaves of the lower plane closely 

 imbricate, ascending, obliquely ovate, obtuse, thick, rigid, mi- 

 nutely ciliate, green above, paler below, becoming reddish-brown 

 in age ; leaves of upper plane nearly as long, obliquely ovate, 

 obtuse; spikes 3" 6" long, quadrangular; bracts deltoid, 

 acutely keeled. Texas to Arizona. 



S. PILIFERA A. Br., is reported from Texas by Mr. Baker, 

 attributing its collection to Wright. An examination of 

 Wright's specimens in the Harvard Herbarium fails to detect 

 this species. It may possibly be found in Western Texas, since 

 it grows in Mexico. It differs from the foregoing by having 

 the primary branching varying from flabellate to pinnate, and 

 the leaves cuspidate and serrulate. Collectors in the South- 

 west should carefully search for this form. 



ORDER VIII. ISOETACE^E. 



Plant-body consisting of a bilobed or trilobed trunk emitting 

 dense tufts of roots, and sending up a compact rosette of rush- 

 like leaves, submerged, amphibious or sometimes growing in 

 moist soil. Sporangia sessile in the axils of the leaves, some 

 containing macrospores and others microspores. Contains a 

 single genus widely distributed. 



I. ISOETES L. QUILLWORT. 



Stem or trunk a more or less depressed, fleshy corm, rooting 

 just above its bilobed or trilobed base, covered above with the 

 dilated and imbricated bases of the awl-shaped or linear leaves. 

 Sporangia large, orbicular or ovoid, plano-convex, very thin, 

 sessile in the axils of the leaves and united at the back with 

 their excavated bases ; those of the outer leaves filled with 

 spherical macrospores ; those of the inner leaves filled with 

 minute and powdery, grayish, obliquely oblong and triangular 



