POPULUS SALICACE^ 623 



high and 2-8 feet in rtiatneter, with thick dark longitudinally Assured bark 

 and stout spreading branches : buds shining and viscid: leaves broadly 

 ovate to oblong-lanceolate, acuminate, narrowed, rounded or subcorcate at 

 base, 2-10 inches long, finely puberulent when young, dark green aboye, 

 pale beneath : petioles usuallv an inch or 2 long : staminate amenta dense, 

 1-3 inches long, its bracts slightly villous : pistillate aments becoming 6-10 

 ihches long in fruit, pubescent: capsule subglobose pubescent, 3-4 lines in, 

 diameter 3-valved : styles 3, broadly dilated and lobed : seeds light-colored. 

 Common along streams, Brit. Columbia to California and the Bocky Mts. 



P. deltoldes Marsh Arb. Am. 106. A large tree 100-150 feet high 

 and 5-8 feet in diameter, with grayish green bark somewhat rough 

 when old : leaves glabrous, broadly deltoid-ovate, abruptly acuminate at 

 the apex, crenulate, truncate at base, 4-7 inches long : petioles flattened 

 laterally, stout, about as long as the blades : bracts glabrous, deeply fim- 

 briate : staminate aments drooping, 3-5 inches long : pistillate amenta 

 loosely fiowered, becoming 6-10 lines long in fruit : capaule ovoid, acute, 

 4-5 lines long, 2 -4-valved, shorter than or equalling their pedicels. Along 

 streams, eastern Washington to the Eastern States. 



P. tremnloides Michx Fl. ii, 243. Usually a shrub or small tree 

 6-30 feet high, but sometimes attaining a height of 100 feet and 3 feet in 

 diameter, with smooth light green bark : leaves broadly ovate or orbicular 

 short acuminate, finely crenulate and ciliate, truncate, rounded or subcor- 

 date at base, 1-3 inches broad: petioles about as long as the blade, flatten- 

 ed laterally, causing the lesiyes to quiver in the slightest breeze ; bracts silky, 

 deeply 3-5-cleft into linear lobes : staminate aments 1-3 inches long, the 

 pistillate longer, dense : stigma-lobes linear : capsule conic, acute, 2-valved, 

 about 3 lines long. Common in moist places, California to Alaska and 

 aoross the continent. 



Subclass 2 ENDOGEN^. 



Stems with the woody fibres scattered irregularly, not form- 

 ing a separate zone of annual woody layers between the bark 

 and pith. Leaves mostly parallel- veined, alternate, entire, 

 sheathing at base. Floral envelopes usually in threes. Em- 

 bryo with only one cotyledon. 



SYNOPTICAL KEY to the ENDOGENOUS ORDERS. 



A Herbaceous perennials with conspicuous perianth. Ovary 

 inferior. 



93 Orchidaceae Leaves mostly flat and not grass- like : flowers perfect, 

 irregular: stamens and style cohesrent: anthers lor 2: capsule 1-celled, 

 with 3 parietal placentse : Seeds numerous, with obscure embryo and 

 no albumen. 



94 Iridacege Leaves equitant and grass-like: flowers regular, perfect, 

 spathaceous : stamens 3, at the base of the perianth : capsule 3-celled : 

 embryo distinct, with albumen. 



B Perianth regular or none. Ovary superior or nearly so. 



* Perianth colored, at least the inner series: carpels united into a 

 compound ovary : seeds with albumen. 



95 Smilacese Woody plants climbing by tendrils: flowers dioecious, 

 6-parted : anthers 1-celled : fruit a berry. 



