346 SYSTEMATIC BOTANY. 



one of which, Salix, is rich in species, is at once distinguishable by the 

 2-valved fruit having numerous seeds clothed with silky hairs. The 

 2-carpellary ovary and the inflorescence connect them closest with 

 Betuiaceae. By some they are placed near Tamariscaceae. The Willows 

 (tialiv) and Poplars (Popidus) belong to temperate and cold climates. 

 Some are valuable for their timber j the young shoots of Willows furnish 

 material for basket-work ; and the bark has usually febrifuge properties, 

 depending on the presence of Salicine. Populus nigra is the common 



Fig. 436. 



Fig. 437. 



Fig. 4.%. (J catkin of Willow. 



Fig. 437. d male and ? female flower of Populus. 



Black Poplar, of which the Lombardy Poplar appears to be a fastigiate 

 variety ; P. tremula is the Aspen ; P. alba is the Abele, or White Poplar. 

 Salix babylonica is the Weeping Willow ; Sallows and Osiers are the 

 shoots from pollard stumps of Salix mminalis, vitellina, &c. ; Salix alba is 

 the ordinary Willow-tree found by river-sides. Willow-wood is used to 

 some extent in turning, on account of its white colour, and it is esteemed 

 lor making charcoal. 



CASUARINACE^E are pseudo-leafless trees with pendulous, jointed, 

 striated branches, the nodes sometimes with short toothed sheaths (whorls 

 of leaves) ; flowers in spikes, diclinous ; the barren flowers in loose spikes, 

 with 2 bracts and 1 or 2 sepals, the latter adhering at their points ; stamen 

 1 ; anther 2-celled ; the fertile flowers in dense spikes or heads, 

 with 2-4 bracts ; ovary 1-celled, with 1-2 ascending ovules ; fruit a 

 collection of follicles aggregated with the bract into cones ; seeds aperi- 

 spermic, with a superior radicle. The species form a small group consisting 

 of trees of remarkable aspect, the branches having much the appearance 

 of the branched Eqitiseta. The jointed stems and abortive leaves connect 

 them also with Ephedra among the Gymnosperms, to which they approach 

 also in the very reduced character of the flowers. The bracts or perianth- 



