366 



TROP/EOLACE/E. 



[Hypogyimous ExOfiENS. 



Order CXXIX. TROP^EOLACEiE.— Indian Cresses. 



Tropaeolea?, Juss. Mem. Mus. 3. 447. (1817) ; DC. Prodr. 1. 683. (18241 ; Endl. Gen. eclviii. - Limnan- 

 there, R. Br. in Lond. and Edinb. Philotoph. Mag. July 1833; Lindley Bot. Reg. t. 1673. (1834) ; 

 Nixus Plantarum,p. 11. (1833) ; Martins Conspectus, No. 272. (1835) ; Endl. Gen. eclix. 



Diagnosis. — Malval Exogcns, with free stamens, no disk, seeds without albumen, and 



an amygdaloid embryo. 



Smooth herbaceous plants, of tender texture and with an acrid taste, trailing or twin- 

 Leaves alternate, without stipules. Peduncles axillary, 1 -flowered. Flowers 



yellow, scarlet, orange, or even blue ! Sepals 3-5, 

 the upper one with a long distinct spur ; aestiva- 

 tion usually valvate, or very slightly overlapping. 

 Petals 1-5, hypogynous, equal or unequal, with 

 a convolute aestivation, sometimes partially abor- 

 tive. Stamens 6-10, perigynous, distinct ; an- 

 thers innate, erect, 2-celled. Ovary 1, 3-cor- 

 nered, made up of 3 or 5 carpels ; style 1 ; stig- 

 mas 3-5, acute ; ovules solitary, erect, or pendu- 

 lous. Fruit indehiscent, the pieces separable 

 from a common axis, sometimes winged. Seeds 

 large, without albumen, filling the cavity in which 

 they lie; embryo large ; cotyledons 2, straight, 

 thick, consolidated into a single body, or distinct; 

 radicle next the hilum. 



Indian Cresses form an Order standing on the 

 limits between the Malval and Geranial Alli- 

 ances. Its valvate calyx is almost the only cha- 

 racter which determines its preference for the 

 former ; for if that were imbricated and ribbed 

 there would be little to separate Indian Cresses 

 from the Cranesbills. Tropceolum majus has 

 the very spur of a Pelargonium, only in the latter 

 the spur is adnate to the flower-stalk. Limnanths, 

 which Dr. Brown first proposed as a distinct 

 Order, do not seem to be naturally distinguished, 

 and, considering the very small extent of the 

 Order of Indian Cresses, are far better combined 

 with them. If the leaves of Limnanthes Dou- 

 glasii and Tropseolum majus are chewed, their 

 flavour is so similar that one is hardly able to 

 distinguish them. The principal difficulty in 

 the way of stationing Limnanths with Indian 

 Cresses, consists in the perigynous insertion of 

 the stamens of the former ; but in this instance 

 other considerations must, I think, outweigh 

 that circumstance. Perhaps Limnanths should 



Fig CCLIV. 



rig. ccliv.— I. Chyinocarpua pentaphyllus ; 2. :i longitudinal section of its Mower; 3. ovary of Tro- 

 psolum majus; i. a vertical section of a carpel, showing the position of the ovule ; 5. a perpendicular sec- 

 tion of a seed 



