192 



DE CANDOLLE'S SYSTEM. 



JOS 307 



302. Theca of Trichopteris excelsa (GleicJteniaceai). 303. The same of Schizaca 

 pectinata (Osmundacece). 304. Part of the frond of Aspidium Lonchitis (Polypo- 

 diacece). 305. Bernhardia dichotoma (Lycopodiaceai). 306. Part of frond of Daval- 

 lia pyxidata (Polypodiacea). 307. Theca of the same. 308. Part of frond of As- 

 pidium exaltatum. 309. Theca of Bernhardia dichotoma (Lycopodiacea). 310. 

 Lycopodium annotinum. 311. A scale and theca of the same. 



1 86. Equisetacea. Leafless branched plants with a striated 

 fistular stem ; the articulations separable, and surrounded 

 by a toothed sheath. Spiral vessels very few. Inflorescence 

 consisting of peltate scales. Reproductive bodies in the inside 

 of the lobes of the scales. Four clavate bodies, wrapped 

 round a naked spore. 



USES. The hard, flinty skin renders them fit for polishing 

 purposes, for which some are used under the name of Dutch 

 rushes. 



TYPICAL GENUS. Equisetum. 



1 87. Characea. An axis, consisting of parallel tubes. Or- 

 gans of reproduction : succulent globules, containing filaments 

 and fluid, and axillary nucules, formed of short tubes, twisted 

 spirally. 



USES. Unknown. 



TYPICAL GENERA. Chara, Nitella. 



188. Bryaceee, or Mmci. Cellular plants, having a distinct 

 axis, covered with minute leaves. Reproductive organs of 

 two kinds : viz. axillary, cylindrical stalked sacs, contain- 



