3. Lycopodium carolinianum L. Slender clubmoss. Fig. 5. 



Peduncles slender, rigidly erect, to 25 cm. tall and 1.5 mm. in diameter; cones 

 1-5 cm. long and about twice the diameter of the peduncle; leaves of the peduncle 

 subulate, in whorls or scattered, about 5 mm. long; sporophylls broadly ovate to 

 deltoid, acuminate, about as long as the peduncle leaves. 



Rare in depressions in savannahs, seepage areas and open flat pinelands in s.e. 

 Tex., July-Sept.; from Fla., n. to N.Y., w. to Tex.; also occurring as variants in 

 S.A., Asia, Afr., Austral, and N.Zeal. 



The erect slender peduncle with scattered small leaves and sporophylls different 

 from the foliage leaves is distinctive. 



Fam. 3. Selaginellaceae Mett. Spikemoss Family 



Small terrestrial or saxicolous plants of spreading habit, prostrate to ascending 

 or suberect, usually profusely branched, with slender stems; stems leafy, usually 

 producing wiry elongate rhizophores at some or all the nodes; leaves all alike or 

 of two kinds, elliptic to lanceolate, several-ranked or in two planes, numerous, 

 minute, 1 -nerved, obscurely ligulate, approximate to widely imbricate; sporophylls 

 somewhat modified, borne in compact sessile cones at the apex of branches; 

 sporangia of two kinds (plants heterosporous), solitary in the axils of sporophylls, 

 1 -celled; megasporangia containing 1 to 4 rather large megaspores; microsporangia 

 containing numerous microspores. 



Only one genus in the family. 



1. Selaginella Beauv. 



Characters same as those of the family. About 700 species are recognized in 

 this complex genus that is highly developed in tropical and subtropical regions of 

 both hemispheres. 



1. Selaginella apoda (L.) Spring. Meadow spikemoss. Fig. 6. 



Plants prostrate-creeping or ascending (especially when in dense shade), pale- 

 to dark-green, flaccid, frequently forming large mats, annual; stems very slender, 

 filamentous, somewhat angled, much-branched, to 25 cm. long or more; leaves 

 dimorphic, membranous, spreading in 2 planes; lateral leaves 2-ranked, alternate, 

 distant, spreading, obliquely ovate to ovate-elliptic, obtuse to acute, with the 

 margins serrulate, 1.5-2 mm. long, about 1 mm. wide; dorsal leaves smaller than 

 the lateral leaves, ovate to ovate-lanceolate, shortly cuspidate, with the margins 

 serrulate, about 1.2 mm. long, less than 1 mm. wide; spikes obscurely quad- 

 rangular, 5-20 mm. long, 2-4 mm. in diameter; sporophylls about as long as 

 the lateral stem leaves, ovate to ovate-lanceolate, acute to subacuminate, keeled 

 in the upper half; megasporangia yellowish, 0.5-0.9 mm. in diameter, most abun- 

 dant toward base of spike; microsporangia reddish, very small, less than 0.1 mm. 

 in diameter. 5. ludoviciana A. Br. 



In moist or wet places, usually in partial shade, in e. Okla. and e. and s.e. 

 Tex., w. into the Edwards Plateau and Rio Grande Plains, May-Dec; from Me. w. 

 to B.C., s. to Fla. and Tex. 



Fam. 4. Isoetaceae Reichb. Quillwort Family 



Small herbaceous perennial aquatic or terrestrial sedgelike plants with short 

 unbranched 2- to 5-lobed subterranean cormlike rhizomes that produce numerous 

 branched roots and a tuft of compact erect or recurved rushlike leaves (sporo- 

 phylls); leaves bearing a small membranous ligule on the inner surface just above 

 the sporangium; sporangia of two kinds, sunken in the axils of the leaf bases, more 



41 



