304 



COLLEGE BOTANY 



Gymnospernue,* 

 or cone-bearing 

 plants. 



Spermatophytes, or 

 seed-b earing-^ 

 plants. 



Cycadales or cycads, tropical or 

 sub-tropical, which are fern- 

 like in character, although 

 some of the larger species re- 

 semble the palms. Very 

 prominent in past ages, but 

 less than 100 species exist at 

 the present time. Most 

 primitive of the seed plants. 



Pinales, or true cone-bearing 

 plants. Mostly evergreens. 

 More prominent in the past 

 than at present, but less 

 ancient than the Cycadales, 

 including about 300 species. 

 See page 306. 



Monocotyledons ; the embryo 

 with one cotyledon; stems 

 mostly of parenchyma, with 

 scattered nbro-vascular 

 bundles ; leaves smooth, 

 simple, linear or lance 

 shaped, mostly sessile and 

 with rare exceptions parallel 

 veined ; flowers mostly 

 simple and in the majority 

 of species the parts are ar- 

 ranged in whorls of threes. 

 About 25,000 species. See 

 Angiospermce, or P a ?? e 312. 



true flowerinp; J Dicotyledons * the embryo with 

 olants ) ^ wo cotyledons; stems witli 



h'bro-vascular bundles ar- 

 ranged in a circle about 

 central axis of pith and a 

 well-defined cambium; leaves 

 with petioles, simple or com- 

 pound and net-veined; 

 flowers ranging from very 

 simple forms resembling the 

 most primitive of the Mono- 

 cotyledons to very complex 

 forms, the parts most fre- 

 quently arranged in whorls 

 of fours or fives. About 

 100,000 species. See page 331. 



* The Gymnospermae consist of seven recognized orders : ( 1 ) Cycadofi- 

 licales, (2) Bennettitales, (3) Cycadales, (4) Cordaitales, (5) Ginkoales, 

 (6) Pinales and (7) Onetales. The first, second and fourth are extinct. 

 We will consider the third and sixth only. 



plants. 



