222 JACK'S LETTERS TO WALLK'H, 1819-1821. 



want of precision is in all Roxb's. descriptions, and particularly in 

 his specific characters? He does not seem to have understood the 

 true intention of them, and generally is very much out in the 

 selection of essentialities. Compare in this respect that wonder- 

 ful man Brown, I must send you herewith a Pentandrian species 

 of his, which perhaps yon would not expect from hence, and which, 

 if in time, may enter into Roxburgh: it is Sersalisia obovata, Br. 

 Prodr. X. II. p. 530 259 and woul dbe a Sideroxylon of Linnean 

 nomenclature. 



I have one other very interesting pentandrian for you. Hoya 

 grandiflora, Br.-' 10 a most splendid personage: flowers 2 inches in 

 diameter, red shading into white, corolla thick and polished like a 

 Japan tea tray. The whole plant hirsute!! Hoya viridiflora 2 ' jl 

 I have also found in considerable abundance. 



I have also found a new Begonia. Do yon remember a Myr- 

 toidea from Acheen among the specimens we examined together, 

 with 3-nerved leaves?: I have again found it. and another nearly 

 related species, 202 which I think I must make a genus of. as it has 

 a 1-celled ovary, many ovula attached to parietal receptacles. Bern- 

 few seeded. Xow if the general character of the Myrtoideae are 

 more dependent on their ovaries than fruit, this will not come 

 under any of the present genera. 



Pray what are the affinities of Hippoeratea and Johnia? 

 Their flowers are so exactly alike, that without the fruit they 

 would pass for the same genus, and a 3-celled berry and a 3-cap- 

 suled fruit are not incompatible with a junction. I doubt how- 

 ever their affinity to Aceres. Their resemblance is strong to 

 Rhamneae in habit, but an exalbuminous fruit is against, an 

 Hippoeratea vere exalbuminosa ? They seem to be somewhat in- 

 termediate betwixt Terebinthacea? and Ehamnese. at least as much 

 as between Aceres and Malpighiaa. I confess I do not very well 

 understand the distinction between a calycine nectarial disk and 

 a hypogynous one. 



Nattal, 15 Oct. 1820. I arrived here last night and find a boat 

 going off for Padang, of which I avail myself, as it is the most- 

 likely way of this reaching you. I intended to have put up a 



259. Sersalisia obovata, E. Br. is Sideroxylon Brownii, F. Muell., — 

 a plant of Queensland. It is probable that Jack had not this very plant 

 before him, but some ally. 



260. This Hoya grandiflora cannot be Tylophora grandiflora which 

 is Brown's H. grandiflora, as Jack thought it. 



261. Hoya viridiflora, B. Br. is Dregea volubilis, Benth. 



262. Rhodamnia trinervia, Blume, would be the first: the second R* 

 cinerea, Jack, but really is a variety of the first. 



Jour. Straits Branch 



