CRYPTOGAMOUS OR FLOWEKLESS PLANTS. 



501 



963. Suboi'd. PolypodinefE. Sporangia collected in dots, lines, or 

 variously shaped clusters {sori 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. Snbord. HymenophylleEB. 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. 

 — JUx. Hymenophyllum, Trichomanes. Ferns of very delicate 

 texture, cliiefly tropical. 



965. Subord, Osmundineac. 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 

 Schizcea, Fig. 1293), opening 

 lengthwise by a regular slit. 



966. Subord. OpMoglosseSB. 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. lycopodiacea; (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 



riG. 1295. LycopOdium Carolinianviin, of the natural size. 1296. A leaf from the spike of . 

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

 larger spores (oophoridia) of Selaginella, magnified. 1298. The same, separated. 1299. A burst 

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



