753 



HYDKOCHAIHTACEJI. (FKOG'S lilT FAMILY.) 



Class II. ENDOGENS or M0IV0C0TYL-ED01V8. 



Steins with no manifest distinction into bark, wood, and 

 pith; the woody libres and vessels in bundles or threads, 

 Avhicli are irregularly imbedded in the cellular tissue ; peren- 

 nial trunks destitute of annual layers. Leaves mostly paral- 

 lel-v^eined (nerved) sheathing at base, seldom jointed at base 

 where they join the stem, usually alternate or scattered, 

 entire. Tarts of flower usually in threes. Embryo with a 

 single cotyledon, and leaves of plumule alternate. 



Fiu 



((i b c) :^eed of a monocotyledon in 

 germination, showing (a) cotyledons, 

 (6) seed r.iat, (c) radicle, (a- h- c') The 

 same in a moi"e advanced state, showing 

 la-) two stem-leaves emerging from the 

 cotyledon, (b-) and (c") the roots developed 

 from the primitive radicle, {d) Longitudinal 

 and transverse section of a stalk of maize, 

 showing the arransement ot the fibres and 

 vessels, (c) Similar sections of the trunk 

 of a kind of palm. (/) Cross section of an 

 e.xogen, for comparison. 



Order CV. HYl>ROCHAHITACEiE, L. C. Rich. 

 (Fro(j's Bit Family). 



Aquatic herhs^ nnith dicecio^is or ])olygamoiis^ Tegular 

 flowers on scape-lil^e 2>cdundes from a sjjathe, and simjyle or 

 douhle floral envelopes^ lohich in the fertile floioers ar&imited 



