same error as Loureiro and Roxburgh, he has 

 generalized where he should have dissected, and 

 has thereby been induced to bring together, under 

 his essential generic character "ovarium 2-locu- 

 lare," numerous species having ovarium 4-locuIare. 

 With a view to the correction of these blunders, 

 with the least amount of inconvenience to the 

 science, I propose retaining all the three genera, 

 which can be very well done by merely slightly 

 altering the character of Rivea, and leaving the 

 other two as defined by their original founders. 

 For example, Choisy gives to Rivea a capitate 

 or lamelliform 2-lobed stigma and 4-celled ovary. 

 I propose substituting the word linear for capitate^ 

 and referring all indehiscent fruited, convolvulace- 

 ous plants having the 4-celled ovary, with linear- 

 cylindrical, or lamelliform stigmas, to Rivea, those 

 with 4-celled ovaries and capitate 2-lobed stigmas, 

 to Argyreia^ and lastly, those having 2-celled ovaries 

 and capitate 2-lobed stigmas, to Lettsomia. With 

 this modification, Rivea stands in exactly the same 

 relationship to Argyreia, that Convolvulus does to 



Courtallum, flowering in August and September. 



The specimen is represented glabrous which it 

 is not; the branches being clothed with appressed 

 white villi and the under surface of the leaves 

 are, from the same cause, somewhat shining-silky 

 white. Properly speaking no part of the plant 

 is tomentose, the ramuli being villous, the under 

 surface of the leaves sericious. 



1358. Argyreia till^folia (R. W. Rivea til- 

 l(Bfolia Ch.), twining, greyish pubescent : leaves 

 roundish-cordate, sometimes obtuse, sometimes acu- 

 minate, pubescent beneath, petioled : peduncles short, 

 1-3 flowered : sepals roundish obtuse, afterwards 

 enlarging, corolla inflato-cylindrical : fruit coriace- 

 ous, enclosed within the enlarged calyx. 



Coimbatore and elsewhere, in low moist soil, 

 flowering during the autumnal rains, and maturing 



its fruit in December and January. 



This is a large diffuse species and, when in full 

 flower, a very handsome one, becoming, however, 

 very much the reverse as the fruit, or rather enlarg- 



Ipom(Ba, while Lettsomia forms the transition from ed calyx, as large as walnuts, approach maturity; 

 Argyreia to Ipomrza^ having the indehiscent fruit after which the fructiferous ramuli decay to give 



of the one, and the 2-celled ovaries of the other. 



The characters of these three genera will then 

 stand thus : — 



Rivea. — Fruit indehiscent Ovary 4-celled. Stig- 

 mas 2-linear, cylindrical or lamellate. 



Argyreia. — Fruit indehiscent. Ovary 4-celIed. 

 Stigmas capitately 2-lobed. 



Lettsomia. — Fruit indehiscent. Ovary 2-celled. 

 Cells 2-seeded. Stigma capitately 2-lobed. 



Thus limited, the genera Maripa^ Legendrea, Mar- 

 celliay Blinkworthia ? Humbertia, and Mooravjlia, 

 will probably all be absorbed by Lettsomiaj along 

 with some of the species now referred to Argyreia, 

 such as A. acuta (Ch,), A, aggre^ata (Ch.), A. festiya 

 (Wall,), A. setosa (Ch.), A. elliptica (Ch.), thus limit- 

 ed, our genera will possess precision of outline very 

 favourable for the determination of their species: 

 as they now stand, that is wanting, and determina- 



place to a new series which make their appearance 

 with the rains of June and July. 



1359. Lettsomia aggregata (Roxb. Argyreia 

 ctggregata^ Choisy), procumbent diffuse or climbing, 

 incano-tomentose : leaves ovato-cordate, glabrous 

 above; incano-tomentose beneath, obtuse: pedun- 

 cles a little longer than the petiols, capitately many- 

 flowered: capitulae approximated on the ends of 

 the branches : bracts involucrate, ovato-orbicular 

 very obtuse, whitish, about 3 lines long: sepals 

 ovate obtuse externally white, exterior ones a little 

 longer: corolla about twice the length of the calyx, 

 stamens long, exserted, ovary 2-celled with 2 ovules 



in each cell. 



Courtallum, Pulney mountains, Mysore, &c. 



A diffuse shrub, climbing over trees or sometimes 

 spreading extensively over rocky ground; flowering 

 durina: the autumnal rains. Flowers pink coloured. 



tion IS consequently most difficult, whence we now ^^^^^^^ ^ed, often one-seeded by abortion, inclosed 

 find species of Argyreia, as here hmited, referred j^ ^^^ enlarged persistent calyx. The cymose cap- 

 to Rivea, Argyreia, and even to Ipomrta. it^l^ ^^^ to^ jnuch spread out in the drawing to 



1356. Rivea ornata (Choisy), stems climbing: 

 leaves petioled orbiculato-cordate or reniform, glab- 

 rous above, whitish tomentose beneath: peduncles 

 elongated, spicato-panicled or umbellate : sepals 

 ovato-lanceolate bluntish, 5-6 lines long, coriace- 

 ous, externally villous : corolla slender, tubular, ber- 

 ry smooth. 



Balagh^t mountains, Madras. 



My specimen differs in one or two points from 

 the above character, the peduncles are short and 

 the lobes of the calyx acute, but as it agrees 

 in other respects, I consider these differences 

 of secondary importance, and refer them without 

 hesitation to that species. 



1357. Argtreia fulgens (Choisy), tomentose 

 or villous: leaves lanceolate long acuminate; glab- 

 rous nigrescent above (in drying), argentio-tomen- 

 tose beneath: peduncles shorter than the petiols, 

 brachiately and loosely many-flowered: bracts nar- 

 row lanceolate or wanting: sepals villous, ovate, 

 very obtuse, the exterior ones the smallest, clothed 

 with white villi. 



give an accurate idea of the plant as seen growing. 



1360. Lettsomia setosa (Roxb. Argyreia setosa, 

 Choisy), adpressed hairy: leaves cordato-ovate, or 

 roundish cordate acuminate, glabrous above ad- 

 pressed strigons beneath: peduncles longer than 

 the petiols, rigid, cymosely many-flowered: bracts 

 uniform-orbiculate, obtuse, externally hairy, em- 

 bracing the pedicels and flowers: sepals externally 

 strigouS) ovato-orbiculate obtuse, coriaceous, 2-3 lines 

 long, enlarging with the fruit: corolla campanulate, 

 G-9 lines long, contracted within the calyx; lobes 

 acute, silvery without. 



Malabar. Aboo. Stocks. 



This, I believe, is the same species as that figured 

 No. 851, all except the dissection of the ovary 

 which, under the erroneous belief that the plant 

 figured belonged to Arg. speciosa was added from 

 a genuine specimen of that species, that plate, 

 therefore, except as showing a somewhat different 

 form of this plant, may be considered cancelled, 

 to be replaced by one of the species named so 

 soon as I can get good specimens which I have 

 not at present. 



( 12 ) 



