354 RUTACEAE. {Vou. II. 
2. PTELEA L. Speers: 2 753. 
Shrubs or small trees, without prickles, the bark bitter. Leaves 3-5-foliolate, with entire 
or serrulate leaflets. Flowers greenish white, polygamous, corymbose-paniculate. Calyx 
4-5-parted, the lobes imbricated. Petals 4 or 5, much longer than the calyx, also imbricated. 
Stamens 4 or 5, alternate with the petals; filaments hairy on the inner side, present in the 
pistillate flowers but the anthers abortive or wanting. Ovary flattened, 2-celled (rarely 
3-celled). Fruit a nearly orbicular samara, 2-winged (rarely 3-winged), indehiscent. Cells 
1-seeded. Seed oblong-ovoid. [Greek, Elm.] 
About 6 species, natives of the United States and Mexico. 
1. Ptelea trifoliata L. Three-leaved Hop-tree. Shrubby Trefoil. 
(Fig. 2271.) 
Plelea trifoliata ¥,. Sp. Pl. 118. 1753. 
A shrub or small tree, with a maximum 
height of about 20° and trunk diameter 
of 6’. Leaves long-petioled, 3-foliolate, 
pubescent when young, glabrate when 
old; leaflets ovate or oval, 2’-5’ long, ses- 
sile, crenulate, acute or obtuse, the lateral 
ones somewhat oblique, the terminal one 
more or less cuneate at the base; flowers 
about 5/’ broad, in terminal compound 
cymes; odor disagreeable; sepals 14’/ long, 
obtuse; petals about 3’’ long, oblong; 
samara 8//-9’’ in diameter, the wing 
membranous and reticulated, emarginate, 
tipped with the minute persistent style or 
this finally deciduous. 
In woods, Long Island to Florida, west to 
southern Ontario, Minnesota, Texas and 
northern Mexico. The fruit is bitter and has 
been used as a substitute for hops. The 
foliage has an unpleasant odor. Wood light 
brown; weight per cubic foot 43 lbs. Called 
also Wafer-ash, Swamp-Dogwood, Wingseed. 
June. 
Family 55. SIMARUBACEAE DC. Bull. Soc. Philom. 2: 209. I8II. 
AILANTHUS FAMILY. 
Trees or shrubs, with bitter bark, and mainly alternate and pinnate not 
punctate leaves. Stipules minute or none. Inflorescence axillary, paniculate 
or racemose. Flowers regular, dioecious or polygamous. Calyx 3-5-lobed or 
divided. Petals 3-5. Disk annular or elongated, entire or lobed. Stamens of 
the same number as the petals, or twice as many; anthers 2-celled. Ovaries 
2-5, or single and 2-5-lobed, 1-5-celled; styles 1-5. Seeds generally solitary 
in the cells; embryo straight or curved. 
About 27 genera and 145 species, natives of warm or tropical regions, distinguished from Ru- 
TACEAE mainly by their non-punctate foliage. 
1. AILANTHUS Desf. Mem. Acad. Paris, 1786: 265. f/. 8. 1789. 
Large trees, with odd-pinnate leaves, and terminal panicles of greenish-white polyga- 
mous flowers. Calyx short, 5-cleft, the lobes imbricated. Petals 5, spreading, valvate. 
Disk 10-lobed. Staminate flowers with 10 stamens inserted at the base of the disk.  Pistil- 
late flowers with a deeply 2-5-cleft ovary, its lobes flat, cuneate, 1-celled, and 2-3 stamens. 
Ovules solitary in each cavity. Samaras 2-5, linear, or oblong, membranous, veiny, I-seeded 
at the middle. Seed compressed; cotyledons flat, nearly orbicular. [From the Chinese 
name. ] 
Three species, natives of China and the East Indies. The following has become widely natu- 
ralized in eastern North America. 
