810 Obdeb 157.— MAESILE;AC£L£. 



SuBKiNQDOM, CRYPTOGAMIA, 



Or Flowerless Plants. Vegetables destitute of true stamens 

 and 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, ACROGENS. 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, etc.) 



Order CLVII. MAESILEACEtE. Peppbrwobts. 



Herhs creeping or floatir^, -n-itli tlio leaves petiolate or sessile, circinate in verna- 

 tion. Fruit (sporocarps) t ^i ;ated at the base of the leaves or leafstalks, containing 

 tho capsular sporanges of one kind with 2 kinds of spores, or of 2 kinds with the 

 different spores separated. 



Oen'zrii (i, epecies 20? inhabiting ditches and inundated places in nearly all countries, but 

 obiefly in temperate latitudes. 



1. MARSIL'EA, L. Sporocarps at the base of the leaf-stalks, of one 

 kind, 2-celled, cells transversely many-celled ; spores inserted on each 

 horizontal placenta. — 21 Stems creeping, rooting ; Ivs. petiolate. 



1 M. quadrifolia L ? Glabrous ; prostrate stems slender, wiry, 8 to 16' long ; 

 Ivs. palmately 4-foUate, on iilitorm petioles 1 to 3' high, Ifts. broadly obovato or 

 fan-shaped, obtuse; fr. (sporocarps) round-oval, borne on short, axjUary stalks, 

 and as large as a pepper-corn. — Sent from La. by Dr. Hale. Perhaps the locality 

 is beyond our limits. 



2 M. vestita, a very delicate species, with stems and petioles as fine as threads, 

 with the quaternate leaflets and the very small sessile sporocarps clothed with 

 minute, silky, brown hairs, is sent from Iowa, near the Mississippi R. by Dr. 

 Couzens. It probably grows in lU. Height of Ivs. 1 to 2'. 



2. ISOETES, L. QuiLL-woRT. (Gr. laog, equal, srog, year ; alike 

 all the year round?) Sporocarps oval, raenobranous, 1-celled, immersed 

 in the dilated base of the frond ; spores subglohous, slightly angular, 

 a.ttached to numerous filiform receptacles, those in the outer fruits larger, 

 angular, triple or in 4s, apparently of a different nature. 



I. laoustria L. Lvs. csespitous, subulate, semiterete, dilated and imbricated at 

 base. — -A curious aquatic, in water at or near the margin of ponds and rivers, N. 

 Eng. and Mid. States, often wholly submersed. Lvs. radical, numerous, tufted, 

 simple, 2 to 10' long, somewhat spreading, containing numerous cells divided by 

 longitudinal and transverse partitions. Fr. whitish, rather large, in the excavated 

 base of the leaves which dilated portion is ordinarily as long as wide ; in var. 

 BIPARIA, broader than long; in var. Bngelmannt, longer than broad. 



3. AZOL'LA, Lam. (Gr. ofw, to dry, dXXvfii, to kill ; quickly 



