224 NATURAL HISTORY OF PLAXTS. 



regards the gynaeceum, androceum, and receptacle, formed exactly as 

 in /inoita, and the fleshy fruit is usually the same. They are, how- 

 ever, distinguished at a glance by a character, no doubt of little im- 

 portance in itself, but very easy to recognise ; the gamopetalous co- 

 rolla has three laterally flattened horn-shaped projections. These solid 

 spurs belong to the outer petals, which, united from the base into a 

 short cylindrical or bulging tube, have the organic apex curtailed and 

 incurved, so that altogether they form a vault closely applied to the 

 reproductive organs. But lower down, the median dorsal part of 

 each is swollen into the sort of wing of which we have spoken, and 

 which, more or less obtuse at the apex, rises obliquely or vertically 

 like the leg of a tripod.' The inner petals want this appendage ; 

 they are like the bodies of the outer petals, or much smaller, reduced 

 to small scales, or even quite absent. The receptacle is like a 

 depressed cone ; the stamens are surmounted by a truncate dilatation 

 of the apex of the connective ; each ovary contains an ascending 

 nearly basilar ovule ; and the fruit is either nearly smooth or covered 

 with recurved points, as in A. muricata or several species oi J/jcronoa.- 

 Tlxe genus RoUinia consists of about twenty trees or shrubs found 

 in America, from Mexico to the south of Brazil.' Their habit and 

 foliage are those oi Anoiia, and their flowers are terminal, leaf-opposed, 

 or extra-axillary, solitary or grouped in few- flowered cymes. 



The general arrangement of the flowers of BoUinia is also found in a 

 Sumatran plant which has been named Parartabotn/s ;* except that the 

 ovaries of the latter contain numerous ovules instead of a single one, 

 and the ascending horns on the backs of the petals are nearly cylin- 

 drical, and of the same thickness in every direction. In the latter 

 character, /''('/r/'/r//'//yrVy7/.s' justifies the name given to express its analogy 



• Followiiij,' the development of these organs in sists of free carpels ; but does not point out in 



the bud, we huve seen (Adannonia, viil. 310) which species is observed this peculiurity, whirli 



that in the youn^; buds the outer corolla is at we have not been in a position to verify, 

 first glubular, and with the convex surface per- ^ A. S. H., loc. cit. — A. !)(.'., .l/r'm., 23. — 



fectly sni<K)t!i. Later, a slij;ht ^^ibbosity arises Maht., FI. Bras., Anoiiac, 17, 47, t. (i.' 



on the jiiidiUe of the dorsiil median line of each ScHLTl.., Liniura, i\. 31 1. — Wai.p , Ri-p., i. l«U ; 



petal. This it is, wiiich becoming? more marked ii. 7 IH ; Ann.,\\.'10; iii. 813; iv. r)7 ; vii. 5S. — 



day by d.iy, fnially pnKluces the solid curved 1*L. & Th.. Ann. Sc. yii(., ser. 1, xvii. 30. — 



horn, obtuse at the a|)ex, whicli all authors have (tiuSEn., Fl. liiit, W. Iml., 5. — U. Hn., Adan- 



remarked. It is easy to hhow that the true soma, viii. 268. 



organic ajK'x of the jK-tal is seated far lower * Miy., Fl. Jiid.'Iin/., suppl. i. \'>i; Ann. 



down than that of this soliil Hjiur. ,!/«*. Liii/d. Hat., ii. 43. — H. IiN., AdannuHui, 



» HkmiiaM says (Journ. Linn. Sur., v. 07) viii. 3U),3:;i», 311. -.A>/«/f«(i H. H.,OV».. 2H, yftS, 



that the fruit of C4'rtain species of RoUinia con- n. 32 (neo Auctt,). 



