ON SOTJTH-AMEEICAN APOCTWACEJ;. 143 



The above specimen, with the aspect of a JDipladenia, is only 7 in. long, with a 

 straight, erect stem, with the fragment of another conjoined at the base. The basal 

 opposite leaves are diminished to the size of small ovate bracts ; in the superior axils 

 they are only 3 lines long ; the superior three pairs, 1 in. apart, are erect, l^-lj in. long, 6-9 

 lines broad above the middle, on petioles scarcely 1 line long. The terminal panicle has 

 an erect peduncle bare at its base for 2^ in., and bears, above, 4 flowers f in. apart, 

 on bracteolate pedicels 7 lines long; sepals 5 lines long; basal contraction of tube of 

 corolla 5 lines long, its entire length being 21 lines; segments 7 lines long, 6 lines 

 broad; the colour of the flower is apparently purplish red; the stamens are inserted 

 6 lines above the base of the tube, on a densely pilose ring ; the anthers acuminate, 

 rigid, with 2 basal obtuse parallel prongs ; the compressed filaments are fixed in front 

 above the sinus of the forks, as in R. crassifolius, with which its floral characters corre- 

 spond in all respects. 



PHESTONIA. 



This genus was established by Robert Brown in 1811, upon one of the rare plants 

 collected by Banks and Solander at Rio de Janeiro in 1768. This, however, was only 

 imperfectly described by that celebrated botanist, as he failed to observe the peculiar 

 structure of the fruit, which was also unknown to Kunth, De Oandolle, Endlicher, 

 MiiUer, and the authors of the ' Genera Plantarum.' The latter botanists {op. cit. ii. p. 709) 

 amalgamated with it the genus Hcemadictyon, because in both cases the tube of the 

 corolla is furnished in the mouth with a callous ring and 5 free narrow linear 

 appendages. Under the head of ScBmadictyon the reasons wUl be given more fuHy 

 for refusing to adopt this conclusion. One good discriminating character has been 

 overlooked, viz. the presence of several small stipules upon the transverse ridge at 

 each node, and the involucel of several stipuliform scales where the peduncle of the in- 

 florescence rises laterally out of the ring, which are always wanting in Scemadic- 

 tyon. In the latter genus the peduncle of the raceme is always simple ; in Frestonia it 

 is very shortly branched, each branch densely furnished with almost sessile flowers, 

 forming a capitate head, and the fruit is an elongated coriaceous 2-celled capsule. The 

 inflorescence and floral structure are well illustrated in Delessert's ' Icones ' (v. tab. 51), 

 with one oversight, the 2-celled ovary being shown as 2 distinct ovaries. The following 

 is offered as a more correct diagnosis of the genus. 



Prestonia, R. Br. : Hamadidyon (in parte) auct. Sepala 5, acute oblonga, imbricata, sequalia, aut minora 

 et coriacea vel majora et submembranacea, singula intus squamiilis singulis latis apice denticulatis 

 mimita. Corolla hypocrateriformis ; tvhus late cylindricus, calyce pauUo longior, fauce subcon- 

 strictus et illic annulo calloso integro vel callis plurimis minutis in seriem simplicem disposi- 

 tis signatus, et sub faucem appendicibus 5 squamaceis cum segmentis alternis prseditus; seg- 

 menta 5, acute insquilatera aut dolabriformia, tubo subbreviora, dextrorsum convoluta. Stamina 5, 

 e pilis medio tubi orta; filamenta brevissima; anthera lineares, in conum subcohserentes, apice 

 acuminata, imo incurvatim biaristatse, apicibus interdum subexsertis. Discus cylindricus, margine 



