. 191 . 



nerves, at first sight resembling those of Compositse, but which hardly reach 

 to the base of the lacinine. It is. a curious circumstance that Brunonia 

 should so completely difter from Compositae in the disposition of vessels 

 of the corolla, while' both orders agree in the no less remarkable structure 

 of the jointed filament; a character which had been observed in a very few 

 Compositee only, before the publication of M. Cassini's second Dissertation, 

 where it . is proved to be nearly universal in the order. In the opposite 

 panetes of the ovarium of Brunonia two nerves or vascular cords are ob- 

 servable, which are continued into the style, where they become .approxi- 

 mated and parallel. This structure, so nearly resembling that of Compo- 

 sitae, seems to strengthen the analogical argument- in favour of the hypothesis 

 advanced in the present paper, of the compound nature of the pistiilum in 

 that order, and of its type in phsenogamous plants generally; Brunonia 

 having an obvious and near affinity to Goodenovise, in the greater part of 

 whose genera the ovarium has actually two cells with one or an indefinite 

 number of ovula in each; while in a few genera of the same order, as 

 Dampiera, Diaspasis, and certain species of Scgevola, it is equally reduced 

 to one cell and a single ovulum." R. Brown in Linn. Trans. 12. 132. The 

 habit of this order is very much that of Globularinea?. 



Geography. Natives of New Holland. 



Properties. Unknown. 



Example. Brunonia. 



. CLXXX. PAPAYACE^. The Papaw Tribe. 



Papat^, Aqardh Classes. {\82A) Cariceje, Tnrpin in Atl. du Diet, des Sc. 



^Nat. (?) _ Papayace.t,, Von Martius H. R. M. (1829.) 



Diagnosis. Monopetalous dicotyledons, with regular unisexual flowers, 

 and a superior 1-celled ovarium with 5 parietal placentae. 

 Anomalies. 



Essential Chaiiacter Flotvers unisexual. Calyx inferior, minute, 5-toothed. 



Corolla monopetalous; in the male tubular, with 5 lobes and 10 stamens, all arising from 

 the same line, and of which those that are opposite the lobes are sessile, the others on short 

 filaments ; anthers adnate, 2-celled, bursting longitudinally ; in the female divided nearly 

 to the base into 5 segments. Ovarium superior, 1-celled, with 5 parietal polyspermous 

 placentge ; stigma sessile, 5-lobed, lacerated. Fruit succulent, indehiscent, 1-celled, with 5 

 polyspermous parietal placentss. Seeds enveloped in a loose mucous coat with a brittle 

 pitted testa ; embryo in the axis of fleshy albumen, with flat cotyledons and a taper radicle 



turned towards the hilum Trees without branches, yielding an acrid milky juice. Leaves 



alternate, lobed, on long taper petioles. Floivers in axillary racemes. 



Affinities. It was the opinion of- Jussieu that the genus upon which 

 this order is founded held a sort of middle station between Urticeae and 

 Cucurbitaceae. Auguste St. Hilaire has, however, well remarked upon this 

 subject, that the only relation that it has with Urticeae consists in the sepa- 

 ration of sexes, its milky juice, its habit, which is like that of some species of 

 Ficus, its foliage, which is not vei-y different from that of Cecropia, and the 

 position of its siigmas : and to these he wisely attaches very little importance. 

 Its fruit brings it near Cucurbitaceae ; but its true place is probably in the 

 vicinity of Passiflorese, with which it altogether agrees in the appearance of 

 its testa, in its unilocular fruit with parietal polyspermous placentae, and in 

 its dichlamydeous flowers ; differing, however, widely in its habit and mono- 

 petalous flowers. 



