THE BRITISH WILLOWS ( 



SALIX. 

 GENERIC DESCRIPTION. 



Trees or shrubs differing from Populus in making no suckers, 

 in the absence of stone cells from the bast, and in the presence in 

 the periderm of cells whose walls are thickened on the outer side 

 only, the thickenings suberised not lignified (E. F. Perredes). 



Stipules persistent, deciduous or absent. Leaves petioled, 

 usually alternate, simple, deciduous, entire or serrate. 



Flowers dioecious, arranged in catkins ; catkins erect at least 

 at first, + leafy, usually preceding the leaves or coeval with their 

 early stages ; $ soon deciduous, 2 persistent till the fruit matures ; 

 rachis usually pubescent. Perianth ; bracts entire, pubescent, 

 rarely glabrous, concolorous or discoloured at the tip ; nectary 

 of 1-2 glands ; stamens 2, 3, or more, filaments free or connate, 

 anthers basifixed ; ovaries superior, sessile or pedicelled, 1-celled 

 with 2-4 parietal placentas ; styles long, short or ; stigmas 2, 

 entire or 2-fid ; ovules many inserted on the placentas in the lower 

 half of the ovaries, ascending anatropous. Capsules 1-celled, few- 

 seeded, dehiscing from the top ; valves 2, recurving when mature ; 

 seeds small, wrapped in silky hairs attached to the short funicle ; 

 albumen ; embryo straight, cotyledons oblong plano-convex, 

 radicle short inferior. 



The seeds germinate with great rapidity under favourable 

 conditions, soon losing their vitality otherwise. 



CONSPECTUS OF GROUPS. 



I. Bracts of the catkins not blackened at the tip. Stamens 

 2 or more, free, 

 i. Catkins terminal; bracts concolorous or reddish, and not 

 blackened at the tip ; stamens 2. Very dwarf 

 alpine shrubs. 



1. Herbace^. Leaves glabrous, green on both sides. 



Catkins on short leafy peduncles ; ovaries glabrous. 



2. Eeticulatze. Leaves silky at first, glaucous beneath. 



Catkins on long leafless peduncles ; ovaries to- 

 mentose. 

 ii. Catkins lateral, bracts concolorous ; ovaries glabrous. 

 Trees or tree-like shrubs, mainly lowland. 



3. Pentandr^:. Leaves glabrous, glutinous. Flowers 



with 2 nectaries ; bracts deciduous ; stamens 5 

 (4-8) ; ovaries subsessile. 



4. Amygdalin^:. Leaves glabrous almost from the 



first. $ flowers with 2 nectaries; bracts per- 

 sistent ; stamens 3 ; ovaries long-pedicelled ; stig- 

 mas subsessile. 



5. Fragiles. Leaves soon glabrescent. Nectaries 



single; bracts deciduous; ovaries rather short- 

 pedicelled, attenuate into along style; stamens 2. 



6. Alb.e. Leaves silvery at first, with subpersistent 



pubescence. Nectaries single ; bracts soon deci- 

 duous; ovaries and stigmas subsessile ; stamens 2. 



