Poputus SALICACEAE Salix 



Key to the Genera 



Catkins pendulous; scales laciniate : fls. with a cup-shaped disc at the base: 



buds with several scales 1 . Populus 



Catkins generally erect; the scales entire: fls. with glands at the base: buds 



with a single scale 2 . Salix 



1. Populus Linn. Poplar ;j§H (Yang Shu) 



Trees: lvs. with flattened petioles, mostly ovate or cordate: buds resinous, ivith 

 several scales: catkins pendulous; the scales laciniate: fls. with a cup-shaped disc at 

 the base: stamens 4 or more. About 30 species; 18 in China. (The Latin name.) 



Key to the Species 

 a. Lvs. of the long shoots densely white or grayish tomentose beneath, 



doubly dentate to sinuately toothed : buds tomentose 1 . P. tomentosa 



aa. Lvs. glabrous or pubescent beneath, or thinly tomentose when un- 

 folding : buds glabrous, 

 b. Petioles long, distinctly flattened, at least towards the blades; 

 blades broad at the base. 

 Blades glandular at the base, ciliate on the margin. 

 Lvs. grayish-pubescent beneath when young, crenate-serrate 



and sparingly ciliate on the margins: stamens brownish. 2. P. adenopoda 

 Lvs. glabrous, crenate-dentate and densely ciliate on the 



margins : stamens reddish 3 . P. deltoides 



Glands absent at base of blade; margin not ciliate A. P. nigra 



var. italica 

 bb. Petiole short, 1-2 cm. long, reddish; lvs. broadest above the 



middle 5 . P. simonii 



1. Populus tomentosa Carr. Chinese White Poplar ^SH (Mao Pai Yang; Hairy 

 White Poplar) (R.M.73). Tree, to 10m.; fls. III-IV. North China; locally in 

 An., Ki., Ku. Commonly planted. Fig. 44. 



2. Populus adenopoda Maxim. Chinese Aspen #3i$§ (Hsiang Yeh Yang; Rustling- 

 leaf Poplar) (R.M.74). Tree, to 25 m.; fls. Ill; fr. IV; lvs. nearly glabrous at 

 maturity. Central and western China; locally in An., Ku. Open woods. 



3. Populus deltoides Marsh. Cottonwood fHHStJI (Mei Kuo Pai Yang; American 

 White Poplar) (R.M.81). Tree, to 10 m.; lvs. deltoid. Introduced from eastern 

 North America; locally in Ku. Planted. 



4. Populus nigra Linn. Black Poplar var. italica Koehne Lombardy Poplar J=£§ 

 (Hei Yang) (R.M.79). Tree, to 15m.; fls. Ill; trees of columnar form. Intro- 

 duced from Europe and western Asia; locally in Ki., Ku. Occasionally planted. 



5. Populus simonii Carr. ^j^^fl (Nan Chin Pai Yang; Nanking White Poplar) 

 (R.M.76). Tree, to 15 m.; lvs. rhombic-ovate to rhombic-elliptic. Northern 

 China; locally in Ku. Planted, woodland. 



2. Salix Linn. Willow fpg (Liu Shu) 

 Shrubs or trees: lvs. mostly lanceolate or linear: winter buds ivith a single scale: 

 catkins usually erect; the scales entire: fls. mostly with 1 or 2 glands at the base; 

 stamens usually 2. About 200 species; 100 in China. (The Latin name.) 



Key to the Species 



a. Brs. twisted or contorted: planted in gardens, a small tree 3a. S. matsudana 



f. tortuosa 



72 



