CRYPTOGAMOUS OK FLOWERLESS PLANTS. 



501 



1296 



963. Subord. Polypodiliea;. Sporangia collected in dots, lines, or 

 variously shaped clusters (^S07'i or fruit-dots) on the back or margins 

 of the frond or its divisions, or rarely covering the whole surface, 

 stalked, cellular-reticulated, the stalk running into a vertical incom- 

 plete ring, which by straightening at maturity ruptures the sporan- 

 gium transversely on the inner side, discharging the spores. Fruit- 

 dots often covered, at least when young, by a membrane called the 

 involucre, or more properly the indusium. 



964. Subord. HymeilopliyllliC. Sporangia borne on a vein extended 

 beyond the margin of the frond into a setiform receptacle, sessile, and 

 surrounded by a horizontal complete ring ; otherwise as in the last. 

 — Ex. Ilymenophyllum, Trichomanes, Ferns of very delicate 

 texture, chiefly tropical. 



9G5. Subord. OsmuiUlinCBD. Sporangia variously collected, cellular- 

 reticulated, destitute of any ring (as in Osmunda or Flowering 

 Fern), or with an imperfect trans- 

 verse ring around the top (as in 

 Schizaja, Fig. 1293), opening 

 lengthwise by a regular slit. 



966. Subord. OphioglossCfC. Spo- 

 rangia spiked, closely sessile, naked, 

 coriaceous and opaque, not reticu- 

 lated, destitute of a ring, opening 

 by a transverse slit into two valves, 

 discharging the very copious spores 

 which appear like floury dust. 

 Fronds straight, never rolled up (or 

 circinate) in the bud ! 



967. Ord. Lycopodiacefc (Club-Moss 



Family), Plants with creeping or 

 erect leafy stems, mostly branching ; 

 the crowded leaves lanceolate or 

 subulate, one-nerved. Sporangia 

 single and sessile in the axils of 

 the leaves, sometimes all crowded 

 at the summit under leaves which are changed into bracts and form 



FIG. 1295. Lycopodium Carolinianum, of the natural size. 1996. A leaf from the spike of 

 fructification, \vith the spore-case in its axil, and spores falling out. 1297. A group of four 

 larger spores (obphoridia) of Sel.-iginella, magnified. 1298. The same, separated. 1299. A burst 

 spore-case of Selaginella apus, with its four large spores. 



