14 OUR NATIVE FERNS AND THEIR ALLIES. 



deeply channeled 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 quadrangular, the bracts 

 broadly lanceolate, spreading at maturity with copious mar- 

 ginal cilia (15 20 on either side) ; microspores very abundant 

 throughout the length of the spike, globose-tetrahedral, 0.036 

 0.039 mrn. in diameter, bright yellow or pale orange. (S. are- 

 naria Underw., not Baker.) In sand, Florida, Texas ? 

 f f Spikes ^' or less long ; plants grooving on rocks. 



10. S. rupincola Underw. Stems suberect, somewhat 

 flexuous, 3' 5' high, rooting only from near the base, pinnately 

 branching, the secondary branches mostly very short ; leaves 

 channeled dorsally, closely imbricate, spreading only near the 

 growing tips of the stem, glaucous or cinereous green, tapering 

 toward the apex and ending in a long white denticulate spine 

 I mm. or more long; margins strikingly long-ciliate, 15 20 on 

 either side ; spikes % or* less long, borne laterally on the 

 branches, scarcely quadrangular, the bracts closely resembling 

 the ordinary stem-leaves, so as to render the spikes scarcely 

 distinguishable except for the axillary sporangia; macrospores 

 dark -yellow, 0.240.27 mm. in diameter, strongly and deeply 

 pitted reticulate. New Mexico and Arizona. 



11. S. Bigelovii Underw. Stems slender, 4' 8' long, 

 mostly ascending, flexuous, usually with short ascending pri- 

 mary branches ; secondary branches infrequent and mostly very 

 short ; stems rooting only near the base ; leaves about six- 

 ranked, appressed-imbricate, usually with a distinct dorsal 

 channel, narrowly lanceolate, tapering gradually into a densely 

 spinulose white awn often 0.7 mm. long; margins with 12 15 

 cilia on either side, which are directed forward and usually less 

 than 0.050 mm. long; spikes obtusely quadrangular, mostly on 

 short lateral branches 5 mm. or less long, the bracts short, 

 broadly ovate but otherwise like the leaves. Southern Cali- 

 fornia. 



I 2. STACHYGYNANDRUM Baker. Stem /eaves of two kinds, 

 spreading in two planes, those of the upper plane smaller and 

 more ascending ; bracts uniform. 



* Main stems dectimbent ; root fibres extending to upper nodes. 

 t Stems persistent ; leaves rigid, firm in texture. 



