CROWFOOT FAMILY 247 
which is a small shrub. Leaves alternate, except Clematis and 
Atragene, with the base of the foot-stalk broad and often clasp- 
. ing. In this family are found plants widely differing in ap- 
pearance, but certain characteristics are common to all. The 
flowers in most of the species are regular, but in some they are 
quite irregular, as in the larkspur. So also the flowers of most 
species are complete in having sepals, petals, stamens and _pistils, 
yet some, as for example, the clematis species, have large colored 
sepals while the petals are greatly reduced or are absent. In 
Thalictrum the flower is still further modified, for here not only 
is the corolla absent (10), but in some of the species the stamens 
are found in the flowers of one plant and the pistils in those of 
another. The seeds are contained in carpels which have the form 
of achenes in which there is but a single seed in the casket; of 
follicles when there are numerous seeds in the casket, while in a 
few instances the seeds are enclosed in a fleshy berry (11). Sta- 
mens numerous. Pistils numerous, few, or only one. 
The carpels or seed caskets form a convenient means of divid- 
ing the genera into groups and they should be studied with care. 
Observe the difference between the entirely closed nut-like achene 
(8) and the generally longer seed casket, the follicle (6), with 
its line for splitting when the fruit is ripe (9). 
FIRST GROUP 
(References to figures in this Key are to those at the head of 
Family Ranunculaceae.) 
Seeds in achenes (see Fig. 1). 
Achenes with long plumose tails . Clematis, Atragene 
Achenes grouped around a tall spike (Fig. 12) | Myosurus 
Achenes in rounded or slightly elongated heads (Fig. 2). 
Flowers with only one envelope, but with a short whorl of 
leaves resembling a calyx near the flower (Fig. 4). Hepatica 
Whorl of stem leaves at some distance below the flower. 
Plowersam. an umbel™. 8s). us Anemonella 
Flowers not in an umbel . . . . +. £=Anemone 
Leaves on flower stem, not in a whorl. 
Blowers nmurierous se si es os oe Thalictrum 
One-tlowered' “fo. a x Hydrastis 
Flowers with two envelopes, calyx and corolla, 
Herbs, flowers yellow. 
