Lily-kin and Rose-kin 123 
complex plan. The leaves of some lilies are 
borne in circles, like spokes of a wheel, and those 
of some of the lilies’ cousins are so ranged along 
the stem that a line drawn through the point of 
insertion of each will go winding upward in a 
beautifully symmetrical spiral. 
One of the most marked characteristics of Mono- 
colyletons is the veining of the leaves. 
By this alone we can generally tell almost at a 
glance whether a plant is to be classed with the 
lily or with the rose. 
The foliage of the lily-kin generally has what 
botanists call parallel veins (Fig. 24). 
A mathematician would take exception to the 
term, for parallel lines, as we all know, never 
meet, while parallel leaf-veins come together at 
the leaf’s tip. 
But the student of plant-life who called the 
veins of lily-leaves and grass-blades ‘‘ parallel,” 
was probably comparing them to the veins of di- 
cotyledenous foliage, which twist and branch into a 
mesh-work as bewildering as it is beautiful (Fig. 25). 
The leaves of lilies and their kin are almost 
always simple in  outline,—arrow-shaped, _heart- 
shaped, oval, or long and narrow, like blades of 
grass, 
