412 OBDEU 156. MARSILEACE^E. 



SUBKIXGDOM, CKYPTOGAMIA, 



OR FLOWERLESS PLANTS. Vegetables destitute of true stamens 

 jind pistils, gradually descending to a mere cellular structure, 

 with reproductive organs of 1 or 2 kinds, producing, instead of 

 seeds, minute, dust-like bodies (spores) having neither integu- 

 ments nor embryo. 



PROVINCE, ACROGrENS. Flowerless plants, having a regular 

 stem or axis which grows by the extension of the apex only, 

 without increasing in diameter, generally with leaves, and 

 composed of cellular tissue and scalariform ducts. (Ferns, 

 Mosses, Club-mosses, Horsetails, &c.) 



ORDEU CLVI. MARSILIACE^E. PEPPEUWOUTS. 



Herbs creeping or floating, with the leaves petiolate or sessile, circinate in 

 vernation. Fruit (sporocarps) situated at the base of the leaves or leaf- 

 stalks, containing the capsular sporanges of one kind with 2 kinds of spores, 

 or of 2 kinds with the different spores separated. 



* Leaves compound, on slender petioles, with 4 leaflets. Steins creeping MARSILIA. t 



* Leaves simple, grass-like, r;idicl. Stem a conn ISOKTKS. 2 



* Leaves minute, iobed, imbricated. Stem filiform, floating free AZOLJ..V. 3 



1. MARSILIA, L. Sporocarps at the base of the leaf-stalks, of one 

 kind, 2-celled, cells transversely many-celled, separating into two lobes at 

 maturity. Sporangia inserted on each horizontal partition, of 2 kinds, 

 some 1-spored, others cc-sporcd. if Stems creeping and rooting. Leave* 

 petiolate, apparently radical, 0/4 whorled leaflets, resembling clover. 



1 Iff, quadrlf'olia L. Lft*. round-cuneiform, as broad as long, glabrous ; sporocarpa 



oblong, smoothish, 1, 2, or 3 on each short peduncle, as large as a peppercorn. 2j Pet- 

 ioles 3 5' high. Margin of pond, Litchfield, Conn. (Prof. Eaton). Leave? floating. 



2 M . vestita Hook & Qiev. Lfts. cuneiform-obovate, longer than broad, glab. ; sporo- 



carps glob. -oval. 2}", hisp.. 1 only on each short (3") peduncle, Z-tooffted on back. S-W. 



3 M, iiiiciuata. Braun. Lfts. cuneiform-obovate, hispid, petioles 1 2' high ; sporo- 



carpx 2", suVs8sil(5 at (he base of the jietioies, clothed with rust-colored wool. Iowa. 



2. ISOETES, L. QI.ILIWORT. Sporocarps oval, l-celled, of 2 kinds, 

 sessile in the axils of the radica.. vs. and adhering to them. Spores in the 

 outer sporangia larger, globular; in the inner minute, powdery. U? 

 Leaves linear, grass-like, clustered on the short conn. 



* Species growing under water, generally wholly submersed, in ponds, &c. .Noe. 1 3 



* Species growing in shallow water, or in damp grounds, emersed Nos. 41 



1 I, lacustris L. Lvs. 20'. subulate, rigid, erect-spreading ; sporocarps round-ovate, 



unspotted, the larger spores with crested ridges. Varies with the leaves setaceox.* 

 tabulate and recurved, the sporocarps rarely a little spotted. N. 



