272 



FERNS : SYNOPTICAL LIST— LVII. 



Synoptical List, with descriptions^ of the Ferns and Fern- Allies of Ja» 

 maica. By G. S. Jenman, Superintendenty Botanical Garden, 

 Demerara. 



Order VI. — Salviniece. 



Annual aquatic floating herbaceous plants, of small or diminutive 

 size, with imbricating or pinnatiform fronds and membranous major 

 and minor capsules, which are situated in the axils of the leaves be- 

 neath, or in inferior clusters on branched filiform threads, and that con- 

 tain, separately, sporangia of two kinds. 



These are, in size, inconsiderable aquatic herbs, which exist usually 

 in great abundance, floating on the surface of still water, and are espe- 

 cially common in Q-uiana. The known species are about a score or 

 more, which are spread through the torrid and the warm temperate re- 

 gions of both hemispheres. 



Genus I. Salvinia, Schreb. — Capsules membranous, indehiscent, glo- 

 bose, clustered in descending panicles, singly at the end of short pedi- 

 cels, borne among the roots, the smaller, which are fewer, superior, and 

 on longer pedicels, containing few reticulated macrosporangia ; the 

 larger, inferior, more numerous, on shorter pedicels, containing multi- 

 tudinous reticulated microsporangia. 



Small floating aquatic herbs, communal in habit, with serial fronds 

 a more or less shortly-extended rachis, entire, flat or partially folded, 

 with close parallel pinnatiform veins, and tufts of numerous, descending 

 simple villous roots Like the next, all the plants of this genus bear a 

 common general resemblance, differing mainly in the degree of elongation 

 of the axis, and size, form, colour and vestiture of the leaves, &c. The 

 capsules are globose, and hang in loose clusters among the leaves, each 

 one on separate pedicels which radiate more or less from the common 

 axis. Those containing the macrosporangia, though situated above, 

 reach out beyond those containing the microsporangia, which are larger, 

 having pedicels twice or more as long. The fruit, roots, and fronds 

 all spring from the joints in the rachis, which is the thickness of mode- 

 rately thin string, the intevening space being destitute. 



1. S. auriculata, Aulet. — Rachis horizontal, cord-like, nearly a line 

 thick, puberulous with slight scales, extending a few inches and branch- 

 ing ; fronds contiguous or apart, two at each joint, spreading at right 

 angles, on petioles J - J in. 1. which are clothed like the rachis, the 

 blades folded at first, rounded, cordate at the base with rounded 

 auricles, | - f th in. each way, herbaceous, cloudy green, pubescent 

 beneath, densely strigose above with elongated glands that are 

 divided into three or four filaments at the end, and mixed with 

 finer ones ; veins very close and numerous ; capsules of micros- 

 porangia nearly 1 li diameter about 2-6 in number, those of the ma- 

 crosporangia half the size and about 1-3 ; both pubescent. — Aubl. guian. 

 2,969 t, 367. Bak. Fern Al. p. 136 8. rotundifolia, W. 8. Eispida, 

 H. B. K. 8. hilohay Baddi. I have not seen Jamaica species but in- 

 clude it to be looked for, for it is probably found on some of the Bri- 



