NATURAL HISTORY OP PLANTS. 



In certain species of Bur sera, described under tlie name of Pro- 

 tium,^ in Asia, and of Tcica,'^ in tropical America, the leaves arc im- 

 paripinnate or reduced to three folioles, usually entire, or even to a 

 single one ; the flowers have four or five parts ; the fruit has an 

 exocarp which is divided more or less distinctly in to panels of stones, 

 and these are united by a slightly résistent columella. In the true 

 Burseras of tropical America (fig. 269-274), the flowers are polyga- 

 mous, 3-5-merous ; the columella of the fruit is of greater con- 

 sistence, the exocai-p is detached more distinctly, usually in three 

 divisions ; the leaves collected towards the summits of the branches 

 have three or a less number of thin and entire folioles. The divisions 

 of the calyx, already deep and more elongated in these species, 

 Bia-sem {Idea) ckeaudra. bccome still morc SO iu Certain 



species of Elaphrium^ American 

 plants, glabrous or more often 

 covered with hairs, having pin- 

 nate leaves, often brought together 

 at the summits of the branches, 

 whose folioles, thi-ee or more in 



Fig. 275. Frnit. Fig. 276. Transverse ' 



section of Fruit. numbcr, becomc generally more 

 coriaceous and denticulate ; the rachis spreading out slightly in 

 wings in their intervals. Thus constituted,* the genus Bursera 

 contains forty to fifty species,'^ arborescent, balsamic, with more or 

 less ramified inflorescence. 



At the side of^the Bursera, has been placed, not without some 

 doubt, Crepichspernmm, a Peruvian tree, having nearly the same 

 male flower, but with an isostemous, pentamerous androceum, and 

 whose fruit is a compressed drupe, slightly tetragonal, with two or 

 three monospermous stones. The Balsams (Balsamea) are still 

 more certainly closely allied to the Bursera. In these trees and 



! BuRM. Fl. Iiicl. (1768), 88 (not XVight and 

 Akn.). — March, in Adansonia, vii. 213, 260 ; 

 vlii. 21,62. 



2 AuBL. Guian. i. 337, t. 130-135.— J. Gen. 

 370.— Lamk. Diet. iii. 224; Suppl. ii. 136; III. 

 t. 303.— K. in Ann. Se. Nat. sér. 1, ii. 349.— DC. 

 Prodr. ii. 77.— Spach.Sm/i!. à Bnfon, ii. 237.— 

 Endl. Gen. n. 5932. 



3 Jacq. Stirp. Amer. i. 105, t. 71.— K. in Ai/ii. 

 Sc. Nat. sér. 1, ii. SiT.—TlC. Prodi: i. 723 

 (part.). — Endl. Qm. n. 6931. — March, in 

 Adaii.ioin'a, viii. 22. 



■• Sect. 4 : 1. MarUjnia (CoMMERS.) ; 2. Idea 



(AuBL.) ; 3. Eubursera ; 4. EUiphrium (jAca.). 



» Sw. Obs. 130.— H. B. K. Nor. Gen. et Spec. 

 vii. 26, t. 611-613 {Etnphrium).—T)-Ei.^ss. Ic. Sel. 

 ii. t. 65 {Marir/nid) . — Wight et Ahn. Frodr. 

 i. 177 (/cic«).— Bentu. Suljih. t. 7, 8 {Ela- 

 phrmm).—T!vL. in Ann. Sc. Nat. sér. 3, vi. 368 

 (Elnplirmm), S72 (ioca).— Te. et Ft. in Ann. 

 Sc. Nat. sér. 3, xiv. 297 {Idea), 302.— March, in 

 Adansonia, viii, t. 1, 3 {Protium). — Geiseb. Fl. 

 Brit. W.-Iiid. 173.— Walp. Hep. i. 558 {Idea) ; 

 ii. 830 ; v. 419 {Elaphriim) ; Ann. i. 201 ; ii. 

 289 ; iv. 449 {Idea) ; vii. 547. 



