BLAKE: REVISION OF MAHOGANIES 29 1 



Type species Swietenia mahagoni Jacq. 



Key to Species 



Leaflets subsessile; seeds light brown. 



Leaflets 5 to 9 cm. long, 0.8 to 3 cm. wide i. 5. hmnilis. 



Leaflets 8.5 to 14 cm. long, 3 to 5 cm. wide 2. 5. cirrhata. 



Leaflets distinctly petioluled; seeds dark chestnut-brown. 



Petals and sepals ciliolate; leaflets 6 to 18 cm. long; capsule 9 to 

 15 cm. long; seeds 7.5 to 10 cm. long. 

 Petiolules 1.5 to 7 mm. long; capsule umbonate at apex 



3. 5. macro phylla. 

 Petiolules 6 to 12 mm. long; capsule obtuse. . . .4. 5. candollei. 

 Petals and sepals not ciliolate; leaflets 3.5 to 7.5 cm. long; 



capsule 4.5 to 7 cm. long; seeds 2 to 4 cm. long .5. 5. mahagoni. 



I. Swietenia humilis Zucc. Abh. Acad. Muench. 2: 355. PI. 7. 



1835-36. 



Tree 7 to 10 meters high, about 6 dm. in diameter, with dense head; 

 branchlets gray; leaves with 2 to 5 pairs of leaflets; petiole 3.5 to 5 cm. 

 long, the rachis 1.5 to 7 cm. long; leaflets 5 to 9 cm. long, 0.8 to 3 cm. 

 wide, elliptic-lanceolate to elliptic-ovate, attenuate at apex and pro- 

 vided wnth a flattish cusp 3 to 7 mm. long, cuneate to rounded at base, 

 subsessile, prominulous-reticulate both sides, somewhat paler green 

 beneath; panicles pyramidal, 4 to 12.5 cm. long (including the 2.5 

 to 5.5 cm. long peduncle); pedicels 0.5 to 3 mm. long; calyx i mm. 

 long, 5-lobed about to middle, the lobes deltoid, obtuse to acutish, 

 papillose-ciliolate ; petals obovate-oval, emarginate at the broadly 

 rounded apex, ciliolate throughout, 5 mm. long, 2.8 mm. wide; staminal 

 tube glabrous, the teeth lance-ovate, acute; disk crenate, papillose, 

 about two-fifths as long as ovary; style shorter and stigma narrower 

 than the ovary; fruit 15 to 20 cm. long, 10 to 12 cm. thick, ovoid, 

 obtusely umbonate at apex; seeds about 10 in each cell, light brown, 

 6 to 9 cm. long, 2 to 2.5 cm. wide. 



Type Locality : Dry sunny places near Tehuantepec, Oaxaca, Mexico, 

 altitude about 300 meters. Type collected by Karwinski. 



Specimens Examined: 



Guerrero: Acapulco, 1894-95, Palmer 405. 



Oaxaca: Taretan, 1883, Duges (Gray Herb.). Chivela, April 26, 

 1910, Orcutt 3190. Tonameca, altitude 25 meters, November 9, 1917, 

 Reko 3549. 



Chiapas: Between Santa Catarina and Santa Lucia, December, 

 1906, Collins (photog. of leaves and fruit). 



Guatemala: Near Nenton, Huehuetenango, altitude 915 to 1220 

 meters, December, 1895, Nelson 3533. 



