HOFFMANN: FLORA OF BERKSHIRE COUNTY. 279 
A hybrid between T. cordifoHa and MiteJIa diphylla has been col- 
lected in WilHamstown by Sanborn Tenney {vid. Rhodora, 8: 91, 
1906). 
HAMAMELIDACEAE. WITCH-HAZEL FAMILY. 
HAMAMELIS. Witch-hazel. 
H. virginiana L. Witch-hazel. — Woods; common in the val- 
ley, becoming rare on the plateau. Reaches an altitude of 2000 feet 
in Savoy. 
PLATANACEAE. PLANE TREE FAMILY. 
PLAT ANUS. Sycamore; Buttonwood; Plane Tree. 
P. occidentalis L. Sycamore; Buttonwood. — Flood-plains; 
common in the valley. 
ROSACEAE. ROSE FAMILY. 
AGRIMONIA. Agrimony. 
A. gryposepala Wallr. — Open woods, clearings and roadside 
thickets; common. 
A. striata Michx. — Low ground and moist open woods; common. 
AMELANCHIER. Shadbush; Ju^eberry; Service Berry. 
Key to Amelanchier. 
a. Flowers racemose. 
b. Teeth of the leaves coarse (on average leaves 3 to 5 (6) per cm.); veins 
conspicuous, usually straight, parallel and close together; leaves oval 
to oval-oblong, rarely orbicular; scrawny, slender, often arching 
shrub of a few rocky mountain-tops .1. sanguinca. 
b'. Teeth of the leaves fine (5 to 12 per cm. on average leaves); veins irregu- 
lar, uneciually distant, usually with frequent intermediate shorter ones. 
c. Leaves densely white-tomentose when young, becoming green; lower 
pedicels 7 to 18 mm. long, in fruit 10 to 25 mm. long. 
d. Leaves rounded at the ape.x; petals short, 7 to 9 mm. long; 3 to 12 
dm. high; stiffly upright shrubs forming patches. Shrub of 
rocky mountain-tops or sandy plains in the southern part of the 
valley 1 • ■'<to!oiiifera. 
d'. Leaves short acuminate, petals usually elongated, 10 to It mm. long. 
Flowers apjiearing very early, usually before the leaves. Shrub 
or tree, generally solitary, or few together, widely distributed. 
.1. canadensis. 
