118 



NATURAL HISTORY OF PLANTS. 



Cassia (Senna) obovata. 



and curvature, is surmounted by a style which is tapering, or more 

 rarely dilated and capitate, or ciliate at its stigmatiferous apex. 1 On 

 the posterior wall of the ovary cell is a longitudinal placenta bearing 

 on both of its vertical lips a row of anatropous ovules, indefinite in 

 number, with their micropyles looking outwards from the hilum. 2 

 The pod of Cassia is very variable in form, thickness, and consistency ; 

 it is dehiscent or indehiscent, with the pericarp more or less promi- 

 nent or hypertrophied between the indefinite seeds, to form as many 

 chambers, in each of which is a transverse or oblique funicled seed, 

 with coats of variable thickness, lined by thick fleshy or horny 



albumen enclosing an embryo. This has a 

 straight radicle and parallel, flat or undulate 

 cotyledons. The species that must be 

 retained in this genus 3 are at least two 

 hundred in number. They may present 

 grreat differences in flower 4 and fruit from 

 those described above, and it is on these 

 differences that a certain number of sections 

 have been founded, which are considered as 

 distinct genera by more than one author. 

 Thus the Sennas 6 (Ft., Senes ; figs. 9C-1 02) possess seven fertile 

 stamens, of which the anterior are most developed, with the fruits 

 bivalve or often incompletely dehiscent, and containing vertically or 

 horizontally flattened seeds. This section has been subdivided into 

 Chamcesenna? in whose bivalve, often much flattened pod the seeds 

 are also compressed parallel with the valves ; CAamafistula, 7 whose 

 pod opens incompletely, and contains horizontally flattened seeds; 



Fig. 96. 



Longitudinal section of flower (|). 



1 In C. florihunda the summit of the style 

 is a long narrow hollow cone opening by a little 

 terminal pore. 



2 They have two coats. 



3 H. B. K., Nov. Gen. et Spec, vi. 337.— 

 Benth., Fl. Austral., ii. 280. — Haet. & Soxd.. 

 Ft. Cap., ii. 271.— Walp., Sep., i. 812; ii. 

 904 ; v. 559 ; Ann., i. 257 ; ii. 443 ; iv. 595. 



4 We have been able to follow the develop- 

 ment of the flower, and the symmetry of its 

 parts in C. florihunda, and have found that the 

 flower has two planes of symmetry, intersecting 

 at an angle of 36°. The one belongs only to 

 the calyx, passing between sepals 1 and 3 , and 

 bisecting 2. The other is antero-posterior, di- 

 viding the corolla, androceum, and gynseceuni 

 into two symmetrical halves. 



5 Senna Gjertx., Fnict., ii. 312, t. 146.— 

 Roxb., JFV. Ind., ii. 339. — Batka, in Bot. Zeit. 

 (1854), 12; Mon. der Cassien Gruppe Senna, 

 Prague (I860). — Benth., Gen., 572, 2. To 

 this Bin ni am adds the section Rerpetica (DC, 

 Prodr., ii. 492). 



6 DC, Inf. cit., 493, sect. v. — Jacq., Icon., 

 1. 71, 460; Hurt. Schoenbr., t. 203, 270.— K., 

 M'nilOS., t. 41-43. — Collad., op. cit., t. 3, 7, 

 11.— Biscjt., in Bot. Zeit. (1850), t. 10.— Bot. 

 Mag., t. 810, 1829, 2638.— Bot. Reg., t. 109, 

 1310. 



' DC, loc. cit., 490, sect. ii. — Jacq., Icon., 

 t. 70-73.— K., Mimos., t. 38-40. — Collad., 

 op. cit., t. 5, 6, 8, 10, 12, 13.— Sweet., Fl. 

 Austral., t. 32. — Bot. Mag.,t.6Z3. — Bot. Beg., 

 t. 83, 856. 



