Trees of New York State 275 



RUTACEAE 



Ptolea trifoliata L. 



Hop Tree, Wafer Ash 



Habit — A shrub or small tree 20-25 feet in height with a trunk diameter of 

 6-12 inclies. Trunk straight, slender, bearing a broad, rounded crown 

 of many slender twigs. 



Leaves — Alternate or rarely opposite, compound, 4-6 inches long, 2^/^-3 

 inches wide, consisting of 3 nearly sessile leaflets borne at the top of a 

 stout petiole which is thickened at the base and 2%-3 inches in length. 

 Leaflets ovate or oblong, acute at the apex, cuneate at the base, entirely 

 or remotely crenulate, the terminal usually larger and more contracted 

 at the base than the others, at maturity subcoriaceous, dark green and 

 lustrous above, paler and smooth or pubescent beneath. 



Flowers — Appearing in June after the leaves, greenish white, polygamous, 

 borne intermixed on slender pedicels in terminal, often compound cymes. 

 Calyx 4— .5-parted, with ovate, acute lobes. Petals 4-5 hypogAiious, longer 

 than the sepals. Stamens 4-5, alternate, exserted in the staminate flowers, 

 much smaller or abortive in the pistillate flower. Pistil consisting of an 

 oblong, compressed, puberulent ovary surmounted by a short style and 

 2-3-lobed stigma. 



Fruit — A 2-celled, 2-seeded, orbicuiar, compressed, buff-colored samara sur- 

 rounded by a broad, reticulate wing. Fruits ripen in the late autumn and 

 are borne on long, slender, reflexed pedicels which persist on the twiga 

 during the winter. 



Winter characters — Twigs slender, yellowish brown, lustrous, conspicuously 

 marked by leaf-scars, Avith a rank odor when broken. Terminal bud 

 absent. Lateral buds small, whitish-hairy, rotund, mostly superposed, 

 borne in the upper angle of V-shaped leaf-scars. Mature bark thin, 

 smooth, dark gray, with numerous, oblong, wart-like excrescences. 



Habitat — On rocky, upland slopes about the borders of forests and woods. 



Range — Central New York westward through southern Ontario to Minne- 

 sota, southward to Florida and Texas. Zones A and B. 



Uses — Occasionally propagated as an ornamental plant in the parks and 

 gardens of eastern United States. The bitter principle obtained from the 

 roots is sometimes used as a tonic. 



