WILLOW FAMILY 167 
SAURURUS. L. 
Flowers without a perianth or with a very rudimentary one. Stamens 
and pistils in the same flower; stamens 6 or 8 or less, long and white, 
giving to the spindle-shaped cluster of flowers the appearance of a fully 
developed spike of pure white flowers. Pistil of 2 or more ovary cells 
at base. 
S. cernuus, L. (Fig. 1, pl. 22.) Lizarp’s Tarn. Herb, 2 to 3 ft. high, 
branching. Leaves egg-shaped, heart-shaped at base, with 5 to 9 dis- 
tinct, nearly parallel veins; 2 to 6 in. long, 2 to 3% in. wide, tapering 
at apex to a slender point. Spike of white flowers dense, 5 or 6 in. long, 
on a common flower-stem considerably longer. Swamps and wet borders 
of ponds or streams, southern half of our area and in central and western 
New York. June-Aug. 
Sus-Orper I].—AMENTACEAE. Ament or CATKIN BrEaRERs * 
Stamens and pistils in different flower groups. ‘Trees and 
shrubs. Inflorescence of staminate flowers always in catkins; 
pistillate flowers generally catkin-like. Flowers without a perianth 
or with a very rudimentary one. Leaves always well developed 
and always alternate. 
Trees with compound leaves . . . . . . Juglandaceae 
Trees with simple leaves. . 
Pistillate and staminate clusters on different trees Salicaceae 
Pistillate and staminate clusters on the same tree. 
Ovary 1-celled, 1-ovuled and 1-seeded in fruit Myricaceae 
Famity I.—SALICACEAE. Wittow Faminy 
Flowers all in catkins. Catkins with pistillate flowers not on 
the same tree with those with staminate flowers. A single flower 
consists of a cluster of stamens or cluster of pistils in the axil of 
a bract which is entire, tooth-like, or slit into strips. No perianth 
except a paddle-like projection in case of the willows and a some- 
what cup-shaped disk at the base in poplars. Stamens, in willows 
2 to 5, in poplars numerous. Some willows have permanent 
stipules to the leaves, others and the poplars have stipules which 
fall before the leaf acquires its growth. Fruit a pod (usually 
several attached to the axis of the catkin) with numerous seeds 
each furnished with a silky down. 
* A catkin or ament consists of a group of apetalous flowers, each flower springing 
from the axil of a scale and all arranged spirally on an undividing stem or axis. 
The flowers of an individual group or catkin consist, generally, exclusively either 
of staminate or of pistillate flowers. The axis or stem of the catkin is not, for 
the staminate group, a complete continuation of the branch from which it grows, but 
is attached in the manner of a leaf and falls when its purpose is served, The 
staminate catkins are usually flexible, drooping dangles, while the pistillate aments 
are frequently erect, 
