194 DICOTYLEDONS. CQNIFEIUE. PinilS. 



10. P. compressum, leaves linear very obtuse sessile, stem spikes 

 about 4-flowered. p. 58. Ditches. 



11. P. pusilium, leaves linear opposite and alternate distinct 

 spreading from the base, stem cylindrical, p. 59. Ditches. 



12. P. pcctinatum, leaves distichous setaceous alternate sheath- 

 ing, stipules scarcely any, spike of flowers interrupted, p. 59. 

 Rivers and salt water ditches. 



CLASS III. DICOTYLEDONS. 



Embryo with 2 or more cotyledons. Plumule in the centre of 

 their point of junction : the inferior end of the embryo itself 

 elongated into a radicle, and not containing any secondary ra- 

 dicles in its substance. 



Stem increasing by external layers or additions ; with an evident 

 distinction between bark and wood. Leaves usually veined, 

 rarely nerved. 



Div. I. PerianthyOrJloral covering, if any, single (calyx ofJuss.). 



ORDER I. CONIFEILE. Juss. 



Flowers usually amentaceous, with the anthers and pistils in di- 

 stinct flowers, mostly naked. Barren fl. 1 many-celled, 

 sessile, on scale-like bracteae, or on the axis of the amentum. 

 Fertile Ji. Cupule 1-flowered, almost closed, shaped like a 

 pistil. Perianth adherent, membranous. Ovary 1. Stigma 

 sessile, simple. Nuts 1-celled, 1 -seeded, either solitary or by 

 pairs within the unexpanded cupule, or covered by imbricated 

 enlarged bractese or peduncles forming a cone (strolilus) . Seed 

 pendulous, albuminous. Embryo with two or many cotyledons. 

 Radicle superior. 



Monoecious or dioecious trees, generally abounding with resin. 

 Leaves simple, acerose, opposite or whorled or fascicled. Mirb. 



1. P1NUS. Decand. 



Monoecious. Barren fl. Aments (or Catkins] racemose, compact 

 and terminal, scaly, the scales bearing stamens at the extremity. 

 Slam. 2. Anthers 1-celled. Fertile fl. Aments simple, imbri- 

 cated, the scales acuminated. Ovaries 2. Stigmas glandulose. 

 Scales of the cones oblong, clavate, woody at the apex, umbili- 

 cated and angular. Nuts geminate, 1 -seeded, covered with an 

 appendiculated membrane. Cotyledons digitato-partite. Leaves 

 binous, or many from the same sheath. Decand. 



1. P. sylvestris, leaves in pairs rigid, cones conico-ovate acute as 

 long as the leaves generally in pairs, p. 275. JPbods. 



