Family ANACARDIACEA:# 161 
2. Acer glabrum Torr. Mountain Maple. 
In canyons in the northwestern part of the state. Hat Creek basin; 
Squaw canyon. 
3. Acer negundo L. Boxelder. 
Common all over the state, mostly along streams. Anselmo; Lin- 
coln; Nebraska City; Norway. 
3. ANACARDIACEZ. 
Sumac Family. 
1. Rhus. 600. 
Leaves pinnate, leaflets 9 or more. 
Leaflets pinnate or nearly so; rachis wing-margined. 1. R. copallina. 
Leaflets sharply serrate; rachis not winged. 2. R. glabra. 
Leaves trifoliolate. 
Leaflets 3-lobed, 1.5-2.5 ecm. long; fruit pubescent. 3. R. trilobata. 
Leafiets mostly entire, 3-10 cm. long; fruit glabrous. 
Vines climbing by aerial roots, or trailing, rarely suberect; fruit 
about 4 mm. in diameter. 4. R. radicans. 
Shrubs without aerial roots; fruit 5-6 mm. in diameter. 
5. R. rydbergii. 
1. Rhus copallina L. Dwarf or Black Sumac. 
In the extreme southeastern part of the state. Nemaha; Rulo. 
2. Rhus glabra L. Smooth or Scarlet Sumac. 
Common throughout the state. (Our western forms from Aten, An- 
selmo, Plummer Ford and Thedford may belong to Rhus cismontana 
Greene.) Anselmo; Aten; Emerald; Fairbury; Lincoln; Nebraska 
City; Plummer Ford; Thedford. 
3. Rhus trilobata Nutt. 
Common in the western part of the state. Arapahoe; Belmont; 
Deuel county; Herrick; Long Pine; Pine Ridge; Thedford; Valentine. 
4. Rhus radicans L. Poison-ivy. 
Common in woods and along fences. Lincoln. 
5. Rhus rydbergii Small. Western Poison-ivy. 
In open woods and prairies. Kearney; Long Pine; Minden; New- 
castle; Valentine. 
4. JUGLANDACEA. 
Walnut Family. 
Husk not dehiscent, nut rough; leaflets 11-23; pith chambered. 
1. Juglans. 
Husk dehiscent, nut smooth or angled; leaflets (in our species) 3-9, 
pith continuous. 2. Hicoria. 
1. Juglans. 323. 
Fruit globose; twigs and petioles puberulent; bark brown and rough; 
pith cream colored; no downy pad over the leaf-sear. 1. J. nigra. 
Fruit elongated; twigs and petioles viscid pubescent; bark gray, 
smoother; pith brown; a downy pad over the leaf-scar. 
2. J. cinerea. 
