ROSALS. 469 
the Cordilleras of Peru and Chili. We have already said that its 
tubers are not the roots, but the real subterranean branches of the. 
plant: p (Fig. 428) being the parent tuber, from the evolution of ' 
an eye of which the axis or under-ground stem a has issued; a 
is a branch given off at a node of the primary axis a, at which 
also the root-fibres r are developed; 1, a young tuber, is the 
Fig. 428, Roots and Tubers of the Potato. 
thickened extremity of the branch. As examples of the genus 
Solanum, we may also cite the Black Nightshade (S. nigrum), and 
the Woody Nightshade (8. dulcamara). 
The Nightshade (Solanum nigram) is a herbaceous shrubby plant, 
which grows abundantly under hedges, in woods, by river sides, 
on the walls of cottages, and in cultivated places. It has white 
flowers, producing a black berry, while S. Dalmacara has purple 
flowers and purple berries. An active crystallizable principle, 
Vomitive at first, afterwards narcotic, pervades both fruits. 
The Egg Plant (Solanum esculentum), known as the Mad and 
Jews’ Apple, is a herb originally from tropical Asia, which culture 
has spread along the shores of the Mediterranean and Southern. 
regions of Europe. It is now naturalised in America. Its large, 
shiny, ovoid, generally violet, but sometimes yellow-coloured fruit 
contains a white flesh, which becomes comestible by cooking. The 
Apple of Sodom (S. Sodomeum), a native of South Europe and North 
Africa, contains a greenish pulp which produces headache, mad~ 
a ess, and even death. 
