370 RUTACEAE 
Erect, 1 to 2 ft. high, lower part of stem simple, upper branching, 
striped or somewhat angular. Branches all reaching nearly the same 
height. Leaves oblong, without leaf-stalks. Flowering stems spreading . 
or recurved. Flowers small, sepals ovate, pointed. Styles distinct. Dry 
woods, our area. June-Aug. 
3. L. medium, (Planch.) Britton. (Fig. 3, pl. 85.) Sairr YEL- 
Low Frax. Similar to No. 2. but branches do not recurve, and stems 
are never angular. Most of our area. 
4. L. striatum, Walt. (Fig. 4, pl. 84.) Rincep YeEttow Fax. 
Generally numerous stems together, all erect and branched above; leaves 
generally opposite, lance-shaped. Stem and branches sharply angled with 
about 4 wing-like angles, somewhat viscid. Wet grounds, Mass., and 
southward. Summer. 
5. L. sulcatum, Riddell. Groovep YELLow FLAx. Stem erect, sim- 
ple, branching only at the upper part. Stem and branches winged or 
grooved, at least above. Leaves alternate, lance-shaped, the upper ones 
with glandular hairs along the borders, 3-nerved. In place of stipules 
are dark glands. Most of our area. 
Famity JV.—RUTACEAE. Rve Famitry 
The members of this family in our area are trees and shrubs. 
Flowers bearing stamens on one tree and pistils on another in 
Xanthoxylum, staminate pistillate and perfect flowers on the same 
tree in Ptelea. Sepals 4 or 5 or more, stamens twice as many as 
sepals or equal in number. Petals 4 or 5. Pistils 2 to 5 generally 
united. Fruit a capsule or a winged fruit (samara). Leaves of 
our species compound, alternate or opposite and abounding with a 
pungent or heavy aromatic volatile oil. 
1. XANTHOXYLUM, L. 
Staminate and pistillate flowers on different plants. Sepals 4 or 5 or 
none, petals 4 or 5. Pistils 2 to 5, separate above, but united below. 
Capsule thick and fleshy. 
X. americanum, Mill. (Fig. 6, pl. 85.) Prickry Asn. TooTHacHeE 
Tree. A small tree or more frequently a shrub, sometimes 25 ft. high, 
the stems and often the leaf-stalks prickly. Leaves compound of about 
4 pairs and an odd leaflet. Flowers in umbellate clusters in the axils of 
the leaves, greenish, appearing before the leaves. Calyx none, petals 
4 or 5. Woods, throughout our area. April-May. 
2. PTELEA, L. 
Fiowers perfect or staminate only or pistillate only. Petals and sta- 
mens 3 to 5. Ovary of 2 cells, pistils 2 above. Fruit a 2-celled, 2-seeded, 
broad-winged samara. Leaves 3-foliate; flowers greenish-white in com- 
pound clusters, 
P. trifoliata, L. (Fig. 5, pl. 85.) Turee-LeAvep Hor-rree. Rather 
tall shrub, with 3-foliate leaves, the leaflets egg-shaped, pointed, 2 to 5 
