WOOTON" AND STANDLEY FLORA OF NEW MEXICO. 29 



one kind of stem produced; branching above the base is rare except when the plant is 

 injured. Sometimes, though not frequently, it is somewhat branched from the base. 

 The rather delicate texture and the somewhat spreading, smooth-topped, long sheaths 

 tipped by a row of triangular black dots are characteristic. 



3. Equisetum. hiemale L. Sp. PL 1062. 1753. Scouring rush. 

 Type locality: "Habitat in Europse sylvis, asperis, uliginosis." 



Range: North America north of Mexico. 



New Mexico: Reserve; Gilmores Ranch; near Las Vegas, on the Gallinas River; 

 Rio Grande near Mesilla. 



This is a common rush along the streams and ditches. The form here referred to 

 is that spoken of as E. hiemale intermedium by Mr. A. A. Eaton. 



4. Equisetum robustum A. Br. Amer. Joum. Sci. 46: 88. 1844. 

 Type locality: "Islands of the Mississippi River in Louisiana." 

 Range: New Jersey and Louisiana, westward across the continent. 



New Mexico: Tunitcha Moimtains; Cedar Hill; Mesilla; Mogollon Mountains. 

 Wet ground, in the Lower Sonoran Zone. 



The large scouring rush occurs not uncommonly along the rivers and irrigating 

 ditches at the lower levels of the State. It may not be sufficiently distinct from 

 E. hiemale. 



Order 4. LYCOPODIALES. 



5. SELAGINELLACEAE. Selaginella Family. 



Mosslike terrestrial plants, usually only a few centimeters high; stems slender, 

 branching, erect or trailing; leaves small and scalelike, arranged in 4 to many rows; 

 sporangia 1-celled, globose, of two kinds, \-iz. , megasporangia bearing 4 megaspores 

 and microsporangia bearing many microspores, borne at the bases of the sporophylls, 

 these differing little from foliage leaves. 



1. SELAGINELLA Beauv. 



KEY TO THE SPECIES. 



Plants erect, tufted, with roots only on the lower part; leaves with 

 long terminal bristles and numerous marginal hairs on each 



side; plants grayish green 1. S. rupincola. 



Plants more or less prostrate, forming mats, mostly rooting along 

 the stems; leaves various; plants grayish or bright green. 

 Stems very short, 6 cm. long or less; strobiles erect, 4-angled, 



usually longer than the vegetative branches 2. S. dcnsa. 



Stems longer, 10 cm. or more; strobiles various. 



Megaspores irregularly wrinkled; strobiles erect; leaves 



and short stems frequently much crowded 3. S. wrightii. 



Megaspores not wrinkled; strobiles hardly distinguish- 

 able from the vegetative parts. 

 Stems very slender, wiry, terete; leaves email, ap- 



pressed 4. 5. mutica. 



Stems weaker; leaves lax, dark green 5. S. underwoodii. 



Selaginella lepidophylla, the "resurrection plant," should be found in the Guadalupe 

 Mountains near the southern boundary, or in the limestone mountains of the south- 

 west corner. 



There is a single specimen of a species closely allied to S. arenicola Underw. in 

 the National Herbarium, the label of which states that it was collected at Las Vegas 

 by Plank. There is some uncertainty as to whether the specimen is correctly labeled; 

 for this reason it is not listed here Collectors should look for such a species in that 

 region and farther east and south. 



