Lycopodales.] 



MARSILEACE^. 



71 



Order XXII. MARSILEACEiE.— Pepperworts. 



Rhizocariiae, Batsch. Tab. Aff. (1802) ; Agardh Aph. 111. (1822).- Rhizospermse, Roth. DC. Fl. Fr. .3. 

 577. (1815).-Ilydropteiides, Willd. Sp. PI. 5. 534. (1810). — Marsileaceae, R.Brown Prodr. im\ 

 (1810) ; Grev. Fl. Edim-ns. xii (1824) ; Ad. Brongn. in Diet. Class. 10. liXi. (1826) ; DC. and Duby, 

 542. (182S) ; Marliits, Ic. PL Crt/pt. 121. (1834) ; £'«d;.^CH. xxxiv. -Salvinieae, Juss.inMirb. EUin. 

 853. (1815).— Sal viniace®, Bartl. Ord. Nat. 15. (1830) ; Martins, Ic. Plant. Crypt. 123. (1834) ; Ed. 

 Pr. Endlich gen. xxxiii.— Isoetese, Rich. Bartl. Ord. 16. Endlich. gen. xxxv. — Sal>'iniiiae and Azol- 

 linae, Griffith in Calcutta Journ.,\o\. v. 



Diagnosis. — Lycopodal Acrogens, ictth many-celled radical spore-cases, and the reproduc- 

 tive bodies of tioo different kinds. 



Stemless plants, creeping, or floating ; leaves usually stalked, sometimes .sessile and 

 scaly, occasionally destitute of lamina, and rolled up in vernation. Reproductive organs 

 enclosed in involucres, and of two kinds ; the one, clustered and stalked, or crowded con- 

 fusedly without stalks, and distinct from the second, or mixed with it, or in contact 

 with it ; the other, simple oval bodies, sometimes ha\'ing a terminal nipple, from which 

 germmation unifomaly proceeds. [Stem and leafstalks filled \\-ith longitudinal cells. A 

 central simple fascicle of vessels composed of scalariform ducts and prosenchyma, 

 enclosmg m the middle a quantity of elongated cells containing starch. Leaves with 

 nerves, veins and stomates. — Martius.'\ 



The Order to which Pilularia and Marsilea belong ^ 



consists of floating or creeping plants, often having the 

 cu'cinate vernation of Ferns, with their reproductive oi'gans 

 in close cases, called involucres, springing either from the 

 root, or from the petioles of the leaves. These involucres 

 contain oval bodies of two kuids, one of which has been 

 called anther, and the other capsule. Figm-es of jNIarsilea 

 vestita and polycarpa have been pubhshed by Hooker and 

 Gre^^lle, at t. 159 and 160 of their noble /co^csi^^Y/cw/n. 

 From these, and the more detailed observations of Esprit 

 Fabre, it is clear that the mvolucre of that genus consists 

 of an involute leaf analogous to the carpellary leaf of 

 flowering plants. 



Esprit Fabre has also shoMH, {Ann. Sc. Nat. 2 ser. 7. 221, 

 9. 115 and 381, and 12. 255,) that on the side of a mucila- 

 ginous cord, wliich T regard with Braun as a midrib, pro- 

 ceeding from the involucre when it opens, there arise 

 oblong plates bearing two sorts of bodies packed closely, 

 sometimes intermixed, but sometimes separated, so that 

 each occupies a difierent side of the plates (wliich are leaf- 

 lets). He regards these two sorts of bodies as anthers 

 and o\'ules, and says, that their mutual position is such, 

 that the side which l)ears the ovules is above that which 

 bears the anthers. The " o-vules " are from 10 to 15 on 

 each side, whitish, semitransparent, ovoid, obtuse at one 

 end, and terminated at the other by a nipple. The " an- 



thers " are little flattened parallelopi- 



pedons, rounded at each end. " They 



consist of a membranous sac, very 



thin and ti'ansparent, in which you see 



numerous pollen grains. The latter are 



spherical or elliptical, often pointed 



on one side. When you crush them 



beneath the microscope, spermatic 



granules of extreme smallness are 



seen to come out." Germination of 



this species takes place, according 



to the same observer, from the 



nipple at the pomt. He tliinks, that 



the two sorts of bodies are certainly 



anthers and o^•ules, because, if they are 



left apart in water they putrefy, while, on the other hand 

 together in water, he has seen the sides of the " anthers " burst, and the ' 



Fig. XLIX. — 1. Growing plant of Marsilea pulsescens ; 2. an involucre opened hy 2 valves, from which 

 rises a leaf whope lateral leaflets are loaded with spores ; 3. an involucre which has opened, and from 

 which the sporiferous leaf is disengaging itself ; at A is seen the side which Fabre regards as anthers. 



Fig. XLIX. 



if mixed 

 grains of 



