380 BURSERACEiE. Bursera. 



Oeder XXXV. BURSERACE^. 



By a. Gray. 



Trees or shrubs (all tropical or subtropical), with alternate and pinnately com- 

 pound leaves, no stipules, and small regular flowers, like Rutacece and Simaruha- 

 cece except that the foliage is destitute of pellucid or glandular dots and there 

 is no particular bitterness, but the wood and bark are resiniferous (the juice 

 yielding myrrh, copal, and various balsams). Ovary 2-5-celled, with a pair of 

 collateral pendulous anatropous or amphitropous ovules in each cell (micropyle 

 superior) . Fruit drupaceous or the epicarp valvular-dehiscent ; seeds solitary, 

 without albumen ; embryo with thin contortuplicate cotyledons. Represented on 

 southern borders only by 



1. BtJE/SERA, Jacq. (J. Burser, a botanist of the 16th century.) — 

 Flowers polygamous, 3-5-merous. Calyx small. Petals ovate or oblong, in- 

 serted on the base of annular hypogynous disk, imbricate or induplicate in the 

 bud, above widely spreading. Stamens 6 to 10. Ovary ovoid, 3-celled; style 

 very short ; stigma 3-lobed. Fruit globular or trigonous, by abortion mostly 

 1-celled and 1-seeded; fleshy or coriaceous epicarp 2-3-valved and falling away 

 from the bony endocarp. — Jacq. ace. to L. Spec. ed. 2, i. 471, & Stirp. Am. 94, t. 

 65 (Burseria) ; L. Gen. ed. 6, no. 440 ; Engler in Mart. Fl. Bras. xii. pt. 2, 251, 

 & DC. Monogr. Phan. iv. 36. — American trees or shrubs, some of them copalifer- 

 ous, with pinnately compound leaves, small and white or yellowish mostly pani- 

 cled or fascicled flowers, and small drupes. 



B. gummifera, L. (Gumbo Limbo, Mastic-tkee.) Resiniferous tree, with spongy wood 

 and reddish bark which exfoliates in thin layers (whence the name W. Ind. Birch-tree), 

 glabrous : leaflets 3 to 9, ovate or oblong, acuminate, thinnish, petiolulate (2 or 3 inches 

 long) ; common petiole slender: flowers in lateral panicles from the base of leafy shoots of 

 the season, commonly .5-merous : fruit only quarter inch long ; the brownish husk falling in 

 3 valves from the white and triangular persistent nut. — Spec. ed. 2, i. 471 (Sloane, Jam. 

 t. 199; Catesb. Car. i. t. 30); Lam. 111. t. 256; Nutt. Sylv. ii. 117, t. 79; Chapm. Fl. 68; 

 Engler in DC. Monogr. Phan. iv. 39. Pistacia Simnruba, L. Spec. ii. 1026. ^ — Coast and 

 keys of S. Florida.^ (W. Ind. to Venezuela.) 



B. microph^^Ua, Gra.t. Tortuous shrub or small tree, with trunk 4 to 6 inches in diam- 

 eter, densely branched, glabrous: leaves mostly crowded at summit of branchlets, 11-33- 

 foliolate ; leaflets Imear-oblong, obtuse, thickish, 2 or 3 lines long, sessile on the narrowly 

 margined rhachis : peduncles short, 2-4-flowered, terminating the branchlets : flowers 

 5-merous : petals more or less induplicate in the bud : drupes small, ovoid ; cotyledons very 

 contortuplicate, biternately dissected into linear lobes. — Proc. Am. Acad. v. 155, & xvii. 

 230; Engler, 1. c. 47, 537. — Rocky hills near Maricopa, S. Arizona, Parry, Pringle. 

 (Lower Calif., Xantus, Palmer; Mex., Palmer.) 



B. HindsiAna, Benth. & Hook. ace. to Wats. Bibl. Index, 157, & Engler, 1. c. 58 {Elaphrhim, 

 Benth. Bot. Sulph. 10), which is unifoliolate, and var. RHOir6LiA, Engler, 1. c, which is trifolio- 

 late, are of Lower California. The latter form was collected by Pringle in N. W. Sonora, near 

 the Gulf of California, and may probably occur in S. W. Arizona. 



1 Add syn. B. Simaruha, Sargent, Gard. & For. iii. 260, & Silv. i. 97, t. 41, 42. 



2 On the eastern coast as far north as Cape Canaveral, ace. to Sargent, 1. c. 



