•2(i2 



NATURAL HTSTORY OF PLANTS. 



In certain species of Bursera, described under the name of Fro- 

 tium,^ in Asia, and of Icica,^ in tropical America, the leaves are 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 distinctlj^ in to panels of stones, 

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

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

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

 sistence, the exocarp 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, 

 B,n-sa-a[icica)()ec(,,Hir,,. bccome stiU moro SO iu certain 



species ol" Elaphrhmi^ American 

 plants, glabrous or more often 

 covered with hairs, having pin- 

 nate leaves, often brought together 

 at the summits of the branches, 

 whose folioles, three or more in 

 number, become generally more 

 coriaceous and denticulate; the rachis siireading out slightly in 

 wings in their intervals. Thus constituted,^ the geuus Bursera 

 contains forty to flfty species,^ arborescent, balsamic, with more or 

 less ramified inflorescence. 



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

 doubt, Crepidospernmni., 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 



75. Fruit. 



Fig. 276. Transverse 

 section of Fruit. 



1 BuRM. Fl. hid. (1768), 88 (not Wight and 

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

 viii. 21,62. 



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

 370.— Lamk. Did. iii. 224 ; Suppl. ii. 136; IU. 

 t. 303.— K. in Ami. Sc.A'at. ser. l,ii. 349.— DC. 

 Prodr. ii. 77.— Spach.-SmiY. a Biiffon, ii. 237.— 

 Endl. Gm. n. 5932. 



3 Jaco. Stirp. Amcr. i. 105, t. 71. — K. in Ann. 

 Sc. Nat. ser. 1, ii. 347. —DC. Prorfc. i. 723 

 (pnrt.). — Endl. Qcii. n. 5931. — March, in 

 Adnnsonia, viii. 22. 



* Sect. 4 : 1. Marignia (Commers.) ; 2. Idea 



(AuHL.) ; 3. Euhirsera ; 4. Elnphrium (jAca.). 



^ Sw. Obs. 130.— n. B. K. Nor. Gen. ct Spec. 

 vii. 26, t. 611-613 (Ehp/iriiwi). —Delesh. le. Sel. 

 ii. t. 55 {Marir/nia) . — Wight et Aen. Prodi: 

 i. 177 (/ciCff).— Bentu. Stdph. t. 7, 8 {Eln- 

 phrimn). — Tul. in Ann. Sc. Nat. ser. 3, vi. 368 

 (EJnplinnm), 372 (Irica). — Te. et Pi. in Ann. 

 Se. Nat. ser. 3, xiv. 297 {Idea), 302.— March, in 

 Adansonia, viii. t. 1, 3 (Protium).- — GiJisEii. Fl. 

 Brit. TF.-Ind. 173.— Walp. Pep. i. 558 {Idea) ; 

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

 2S9 ; iv. 449 {Idea) ; vii. 547. 



