RUTACEAE 677 
3. Ptelea serrata Small. An irregularly branching shrub 1-2 m. tall, with gla- 
brous foliage. Leaflets 3, the blades thinnish, oval, elliptic, to elliptic-obovate, 2.5-7 cm. 
long, sharply acuminate, or rarely only acute, rather shallowly serrate, deep green above, 
very pale green beneath, the terminal one with a slender base: panicles few-flowered : 
samaras obovate, 16-19 mm. long, acute at the base, the wing rather delicate, the body 
glandular-dotted. 
On granite rocks, Stone Mountain, Georgia. Spring. 
4. Ptelea microcárpa Small. A branching shrub, 1.5-3 m. tall, with glabrous foli- 
age. Leaflets 3, the blades rather firm, elliptic to oval or elliptic-obovate, 5-10 cm. long, 
bluntly pointed or slightly acuminate, entire or merely undulate, slightly paler beneath 
than above, the terminal one not conspicuously narrow at the base: panicles many-flow- 
ered : samaras obovate, 8-11 mm. or rarely 12-20 mm. long, rounded or truncate at the 
base, the wings slightly crisped, the bodies pitted. 
On limestone or granite ridges or hillsides, Tennessee, Georgia and Alabama. Spring. 
5. Ptelea trifoliàta L. An aromatic shrub or tree sometimes 8 m. tall, the foliage 
glabrous or sometimes densely pubescent. Leaflets 3, the blades ovate, oval, elliptic, oblong, 
oblong-lanceolate or oblanceolate, 4-12 cm. long, acute or acuminate, entire or sometimes 
undulate or partially erenulate : panicles many-flowered : sepals ovate, 1.5 mm. long, ob- 
tuse: petals nearly oblong, 4-5 mm. long: samaras suborbicular or oval-orbicular, 2-2.5 
cm. long, rounded or notched at the base. 
In rich soil or on river banks, Long Island to Ontario, Minnesota, Florida and Texas. Spring.— 
The form with pubescent foliage, is P. trifoliata móllis M. A. Curtis. 
6. Ptelea rhombifólia Heller. A shrub 2-2.5 m. tall, branching above, the foliage 
densely pubescent. Leaflets 3, the blades rhombic-ovate or rhombic-orbicular, 2.5-5 cm. 
long, blunt, crenate, dull green above, the terminal one little longer than broad: petals 
pubescent without, about 4 mm. long: filaments slightly pubescent near the base : samaras 
nearly orbicular, 1.5-2.5 em. broad. 
In open woods, southern Texas. Spring. 
. 7. Ptelea Toxicodéndron Small. A branching shrub 1-2 m. tall, with glabrous 
foliage. Leaflets 3, the blades oval or rarely oval-ovate, 1.5-6 cm. long, rounded or blunt 
at the apex, crenate or somewhat erenate-lobed, dark green and lustrous above, slightly 
paler beneath : panicles few-flowered : petals about 5 mm. long, glabrous : filaments densely 
pubescent at the base: mature samaras not seen. 
In gravelly soil, near Kerrville, Texas. Spring. 
7. AMYRIS L. 
Glabrous shrubs or trees, containing a resinous aromatic sap. Leaves alternate or 
opposite : blades compound, sometimes unifoliate : leaflets with entire or crenulate blades, 
punctate. Flowers perfect or polygamous, in axillary or terminal panicles, white. Ped- 
icels often with 2 scales. Hypanthium urn-shaped. Sepals 4. Petals 4, imbricated. 
Stamens 8, inserted on the disk : filaments filiform : anthers opening lengthwise. Ovary 
l-celled : style short or wanting: stigma flat or capitate. Ovules 2, pendulous from the 
top of the cavity. Drupe obovoid, oval or globose, with a parchment-like stone. Seed 
solitary. Testa membranous. Cotyledons thick. TorcH-woop. 
Leaves alternate: leaflets with crenate blades, the terminal one sessile or RUNE E E 
la à . A. parvifolia. 
ves opposite : leaflets with entire blades, the terminal one long-stalked. i 
Gynophore obsolete, the receptacle flat. 2. A. elemifera. 
Gynophore well developed, surrounded by the elongated receptacle. p 
Leaflets shining beneath : ovary glabrous: fruit globose. 3. A. maritima. 
Leaflets dull beneath : ovary pubescent: fruit obovoid to oval-elliptic. 4. A. balsamifera. 
l. Amyris parvifolia A. Gray. An unarmed glabrous aromatic shrub 1-3 m. tall, 
usually densely branched, the twigs and inflorescence densely glandular. Leaf-blades 
8-foliolate, petioled : leaflets 3, the blades leathery, 1-2.5 cm. long, ovate, obtuse, coarsely 
Crenate, sessile or nearly so, firm, punctate on both sides: panicles 2-3 cm. long: flowers 
in terminal corymbose panicles : calyx 1 mm. broad: sepals broadly ovate, acute, 1-1 as 
long as the thick, club-shaped pedicel : petals 1-2 mm. long, oval, obtuse : stamens included : 
laments and anthers of iie same length. [Xanthorylum Tezamum Buckl.]} 
Along or near the Rio Grande, southern Texas and adjacent Mexico. Spring. 
