216 NORTH AMERICAN FLORA [Volume 25 



23. AMYRIS (P. Br.) L. Syst. ed. 10. 996, 1000. 1759. 



Elemi Adans. Fam. PI. 2 : 342. 1763. 

 Ritinophora Neck. Elem. 2 : 229. 1790. 

 Elemifera (L.) Kuntze, Rev. Gen. 99. 1891. 

 Schimmelia Holmes, Pharm. Jour. London 62: 53. 1899. 



Glabrous or pubescent shrubs or trees. Leaves opposite or alternate, compound, 

 sometimes unifoliolate, petioled, the petioles sometimes winged. Inflorescence ovoid or 

 corymbiform, few-many-flowered, or flowers sometimes solitary. Flowers perfect, in 

 axillary or terminal panicles, white or creamy-white. Pedicels bibracteate. Hypanthium 

 urn-shaped. Sepals 4 or 5. Petals 4 or 5. Stamens twice as many as the petals, inserted 

 on the disk ; filaments filiform ; anthers opening lengthwise. Ovary 1-celled ; style short, 

 terminal, or wanting ; stigma flat or capitate. Ovules 2, pendulous from the top of the 

 cavity. Drupe black or reddish. Seeds solitary ; testa membranous ; cotyledons plano- 

 convex, thick and fleshy, glandular-punctate. 



Type species, Aniyris balsamifera L. 



Leaflets separable into two layers; leaves unifoliolate, alternate. 



Leaflets linear-lanceolate to narrowly lanceolate, attenuate at the apex ; 



primary nerves not joined by cross-veinlets. 1. A. lineala. 



Leaflets oblong to obovate, obtuse or emarginate at the apex ; primary 

 nerves joined by cross-veinlets, usually prominent on the lower sur- 

 face of the uppe'r leaf-layer. 2. A. stromatophylla. 

 Leaflets not separable into two layers. 

 Leaves unifoliolate, alternate. 



Petioles, including petiolules, 2-5 mm. long. . 3. A. monophylla. 



Petioles, including petiolules, 8-20 mm. long. 4. A. simplici folia. 



Leaves 3-11-foliolate. 

 Leaves opposite. 



Leaflets 3 or 5, glabrous or merely puberulent beneath. 



Lateral leaflets cuneate to subtruncate at the base, mostly acute 

 to acuminate at the apex. 

 Lateral leaflets mostly of an obovate type, obtusish or acut- 



ish, 1-3 cm. long, 0.6-2 cm. broad. 5. A. diatrypa. 



Lateral leaflets of an ovate type, acute to long-acuminate, 

 2-13 cm. long, 1-6 cm. broad. 

 Ovary glabrous; branches of the inflorescence glabrous 

 or minutely puberulent ; drupe usually globose or sub- 

 globose, 5-8 mm. long. 6. A. elemifera. 

 Ovary hispidulous; branches of the inflorescence hispidu- 

 lous, sometimes becoming glabrate with age ; drupe 

 usually of an obovoid type, 6-14 mm. long. 7. A. balsamifera. 

 Lateral leaflets cordate at the base, rounded at the apex. 8. A. Purpusii. 

 Leaflets 5-11, tomentulose beneath ; ovary pilose. 9. A. madrensis. 

 Leaves alternate. 



Leaflets 1-3 cm. long, 5-15 mm. broad, the terminal one short- 

 stalked or sessile (4 mm. or less), the stalk not conspicuously 

 jointed below the base of the blade. 10. A. lexana. 



Leaflets 3-10 cm. long, 2-9 cm. broad, the terminal one long- 

 stalked (1 cm. or more), the stalk jointed a little distance 

 below the base of the blade. 

 Leaflets ovate to rhombic-ovate, acute or abruptly acuminate. 11. A . sylvatica. 

 Leaflets oblong-elliptic to rhombic-lanceolate, usually long- 

 acuminate; petioles often winged. 12. A. thyrsiflora. 



1. Amyr is lineata Wright ; Griseb. Mem. Am. 

 Acad. II. 8: 177. 1860. 



Elemifera lineala Kuntze, Rev. Gen. 100. 1891. 



A slender, glabrous tree up to 13 m. in height; leaves alternate, unifoliolate; petioles 

 slender, 3-7.5 mm. long, jointed at the base of the blade, persistent after the falling of the 

 leaflet; leaflets narrowly lanceolate or linear-lanceolate, 2.5-8.5 cm. long, 3.5-20 mm. broad, 

 long-acuminate, acute or obtuse at the apex, cuneate or somewhat rounded at the base > 

 entire, tough, rigid, obscurely pellucid-glandular, separable into two layers, its margin 

 thick, the veins prominent on both surfaces, not reticulate, the primary nerves close 

 together, parallel and directed toward the apex, not joined by cross-veinlets ; flowers soli- 

 tary or several in clusters, axillary ; sepals 4 or 5, triangular, acute or obtuse at the apex ; 

 petals 4 or 5, oblong-oval, obovate or sometimes ovate, 2-2.5 mm. long, 1-1.5 mm. broad, 

 occasionally the petals and sepals are not of the same number ; stamens 8 or 10 ; filaments 



