342 THE CROWFOOT FAMILY 
Most of the crowfoot family are like marsh-marigolds in 
having their leaves petiolate. In some cases there is no 
petiole. The leaf is then described as sessile,! a term applied 
to any stalkless organ of a kind which is commonly stalked. 
As regards their arrangement the leaves of marsh-mari- 
golds are like almost all the others of the family in being 
alternate, 7. e., one at each node. In clematises there appear 
two leaves at a node—such are called opposite—while in 
anemonies there are often more than two forming a ring, 
encircling the stem. Such a ring is termed a whorl or verticil,? 
and the leaves are said to be whorled or verticillate. When 
leaves are opposite they are of course virtually in whorls of 
two. Leaves forming a rosette may approach closely the 
verticillate arrangement, and it becomes a fair question 
whether verticils may not be after all merely rosette-like ~ 
clusters in which the internodes have developed scarcely 
at all.. This view is favored by the fact that internodes of 
perceptible length do sometimes separate the leaves of such 
verticils as those of anemony. Furthermore, in clematises 
the leaves before they expand often show one of a pair dis- 
tinctly shorter (and therefore presumably younger) than 
the other, just as if they were really alternate but with only 
one of every two successive internodes developed. Although 
we may admit that the alternate arrangement passes readily 
into the verticillate even on the same plant, it is of course 
necessary in practical description to distinguish the types. 
Students are sometimes puzzled as to how they may dis- 
tinguish between a leafy shoot and a compound leaf, or be- 
tween simple leaves and leaflets. They will be helped by 
remembering that a stem branch arises normally from the 
axil of a leaf-member, and is an axis bearing leaves in the 
axils of which buds may develop. Conversely leaf-members 
normally subtend,? 7. e., stand just below, a bud or shoot, 
and are lateral members radially disposed about an axis and ~ 
flattened, at least, when young, transversely with reference 
1 Ses’-sile < L. sessilis, sitting. 
2 Ver’-ti-cil < L. verticillus, the whirl or whorl of a spindle, which is 
a disk-like piece of wood or metal encircling it; hence, in botany a 
ring of parts similar to one another encircling an axis. 
3 Sub-tend’ < L. sub, under; tendere, stretch. 
