226 URTICACEiE. Humulus. 



Stems twining with the sun, usually several from one root, very rough downward with 

 minute prickles. Leaves 3 — 5 inches long, with the lobes acuminate and serrate, very 

 rough. Stipules between the petioles, reflexed. Sterile flowers in oblong panicles from short 

 axillary branches. Sepals oblong, obtuse. Fertile flowers in oblong amcnts. Bracts ovate, 

 acute. Caly.x-scales in fruit covered with orange-colored resinous grains. Strobile in maturity 

 1-2 inches long, and about an inch in diameter. 



Borders of woods, hedges, etc. : not rare, and apparently native. Fl. July. Fr. September. 

 The peculiar principle of the hop resides in the yellow granular matter of the strobiles, and is 

 known by the name of lupulin. It is employed in medicine as an anodyne. 



CLASS II. GYMNOSPERMOUS PLANTS. 



Stem similar to that of exogenous plants. Ovules not enclosed in an ovary ; 

 the carpel being either altogether wanting, or represented by an open scale. 

 Embryo with two opposite, or several whorled cotyledons. 



Order CV. CONIFER.^. Juss. The Pine Tribe. 



Flowers monoecious or dioecious, commonly amentaceous, destitute of calyx and 

 corolla. Sterile flowers consisting of one or more (often monadelphous) 

 stamens, arranged on a rachis so as to form a loose ameat or spike. Ovules 

 seated on scales (which may be regarded as flat and open carpels), or in an 

 open disk. — Trees or shrubs, with branching trunks, abounding in resinous 

 juice ; the wood mostly destitute of proper spiral vessels, and consisting of 

 fibres which are marked with circular disks. Leaves scattered, fascicled, 

 sometimes opposite, usually rigid and needle-shaped, entire. 



Suborder I. ABIETINE^E. L. C. Rich. The Pine Tribe proper. 



Flowers usually monoecious. Fertile aments formed of imbricated carpellary 

 scales, each with a pair of inverted ovules adherent to their base. Scales 

 subtended by bracts. Fruit a strobile or cone, the scales of which are woody 

 or coriaceous, and usually persistent. Integument of the seed coriaceous or 

 woody, often produced into a membranaceous wing. Embryo in the axis of 

 fleshy or oily albumen, with 2-15 cotyledons. 



