KUTACEAE 677 



3. Ptelea serrkta 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 microcdrpa 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 trifoMta 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 crenulate : 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 vidllis M. A. Curtis. 



6. Ptelea rhombifolia 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 cm. broad. 



In open woods, southern Texas. Spring. 



7. Ptelea Toxicodendron 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 crenate-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 

 1-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-wood. 



Leaves alternate : leaflets with crenate blades, the terminal one sessile or short-stalked. 



1. ^4. parvifoUa. 

 Leaves opposite : leaflets with entire blades, the terminal one long-stalked. 



Gynophore obsolete, the receptacle flat. 2. A. elemifera. 



Gynophore well developed, surrounded by the elongated receptacle. 



Leaflets shining beneath : ovary glabrous : fruit globose. 3. A. maritima. 



Leaflets dull beneath : ovary pubescent : fruit obovoid to oval-elliptic. 4. A. balsamifera. 



1. Amyris parvifolia A. Gray. An unarmed glabrous aromatic shrub 1-3 m. tall, 

 usually densely branched, the twigs and inflorescence densely glandular. Leaf-blades 

 3-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, \-\ as 

 long as the thick, club-shaped pedicel : petals 1-2 mm. long, oval, obtuse : stamens included : 

 filaments and anthers of the same length. [Xanthoxijlum Texanum Buckl.] 



Along or near the Rio Grande, southern Texas and adjacent Mexico. Spring. 



