SALICACE^E. 



135 



DICOTYLEDONS. 



Vascular bundles arranged in a circle around a central pith, the 

 stem when perennial increasing in size by means of a cambium ring. 

 Leaves with netted veins. Parts of the flower commonly in fours or 

 fives. Embryo with 2 cotyledons. 



CHORIPETALtE. 



Corolla present or absent; when present consisting of distinct 

 petals. 



14. SALICACE/E. Willow Family. 



Trees and shrubs with simple alternate stipulate leaves. Flowers 

 dioecious, arranged in aments (catkins), these falling off as a whole, 

 the staminate after anthesis, the pistillate after the ripening of the 

 fruit and dispersion of the seeds. Bracts of the ament scale-like. 

 Perianth none. Stamens 1 to several. Ovary 1-celled; stigmas 2. 

 Fruit a 2-valved capsule, enclosing many seeds furnished with a tuft 

 of hairs at base. 



Bracts entire or merely denticulate; flowers without disk; stamens in ours 1 to 

 5; stigmas short 1. Salix. 



Bracts fimbriate or lacerate; flowers with a broad disk; stamens numerous; 

 stigmas elongated, conspicuously dilated 2. Populus. 



1. SALIX L. Willow. 

 Leaves mostly narrow, short-petioled. Buds covered by a single 

 scale. Aments (catkins) mostly erect, appearing before or with the 

 leaves; bracts entire or merely denticulate. Stamens (in our species) 

 1 to 5, accompanied by 1 or 2 little glands. Pistillate flowers with a 

 gland at the base of the ovary. Stigmas short. (Classical Latin 

 name of the Willow.) 



Stamens 3 or more; aments terminal on leafy branches; bracts of the pistillate 

 ament pallid or greenish, falling before the fruit matures; bark of trunks 

 rough and fissured; leaves serrulate; trees. 

 Petioles not glandular. 

 Leaves narrowly lanceolate, long pointed, green on both surfaces; stipules 



semi-cordate, acuminate, sometimes deciduous. ... 1. S. nigra. 

 Leaves lanceolate or oblong-lanceolate, acute or acuminate, pale or 



glaucous beneath; stipules commonly none 2. S. laevigata. 



Petioles glandular near the blade; leaves lanceolate, long-pointed, often pale 

 or glaucous beneath; stipules semi-orbicular, mostly conspicuous .... 



3. S. lasiandra. 



Stamens 2, rarely 1; bark smooth. 

 Aments terminal on short leafy branchleis; bracts pallid, often falling before 

 the ament matures; leaves linear to linear-lanceolate, entire or serrulate; 

 occurring mostly as shrubs in our district. 

 Leaves silkv pubescent on both surfaces; stigmas large, sessile 



4. S. fluviati/is 

 var. argyrophyUa. 



Leaves green on both surfaces and more or less glabrous; style short but 



obvious; stigmas linear 5. 8. sessilifolia. 



Aments terminating very short leafless lateral branchlets: bracts dark-colored 

 at apex, persistent in fruit; bark smooth; leaves entire; small trees or 

 shrubs. 



