SALICACE^. 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. 



CHORIPETAL^. 



Corolla present or absent; when present consisting of distinct 

 petals. 



14. SALICACE^. Willow Family. 



Trees and shrubs with simple alternate stipulate leaves. Plowers 

 dioecious, arranged in aments (catkins), these falling oflf 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 

 6; stigmas ^hort ]. Salix. 



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

 stigmas elongated, couspicuously dilated 2. Populds. 



1. SALIX L. TViLLO-w. 

 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 pislillat'e 

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

 rough and fissured: leavfS serrulate; trees. 

 Petioles not glandular. 

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

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

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



glaucous beneath; stipules commonly none 2. S. l3svigata. 



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

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



3. 5. kLsiandra, 

 Stamens 2, rarely 3; bark smooth. 



Aments terminal on short leafy branchle's; bracts pallid, often falling before 

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

 occurring mostly as shrubs in our district. 

 Leaves silky pubescent on both surfaces; stigmas large, sessile 



4. S.fluviatiiis 

 var. argyrophylla. 



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



obvious; stigmas linear .^i 5. sessilifolia, 



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

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

 shrubs. 



