37 



centae in the axis, a calyx with valvate aestivation, 2-celled anthers bursting 

 longitudinally, no disk, and alternate stipulate leaves with stellate pu- 

 bescence. 



AxoiMALiEs. The carpella of Sterculia and Erythropsis are distinct, 

 and their flowers have no petals. True Biittneriacese have five abortive 

 stamens. Waltheria has but one carpellum, four being abortive. 



Essential Character. — Calyx either naked or surrounded with an involucrum, 

 consisting of 5 sepals, more or less united at the base, with a valvular sestivation. Petals 5, 

 or none, hypogynous, convolute in asstivation, often saccate at the base, and variously- 

 lengthened at the apex. Stamens definite or indefinite, monadelphous in various ways, 

 some among them being often sterile ; anthers 2-celled, turned outwards. Pistillum con- 

 sisting of 5, or rarely 3, carpella, either distinct or cohering into a single ovarium ; styles 

 equal in number to the carpella, distinct or united ; ovula erect. Fruit capsular, with 3 or 

 5 cells. Seeds with a strophiolate apex, often winged ; albumen oily or fleshy, rarely want- 

 ing ; embryo straight, with an inferior radicle ; cotyledons either foliaceous, flat, and plaited, 

 or rolled round the plumula, or else very thick, but this only in the seeds without albumen. 

 — Trees or shrubs. Pubescence often stellate. Leaves alternate, simple, often toothed, 

 with stipulse. Peduncles cymose. 



Affinities. I take this order as it is understood by Kunth and 

 Decandolle, without being at all certain that Biittneriaceee, as proposed 

 by Mr. Brown, are not really distinct. As it now stands, it comprehends 

 plants very variable in some of their characters, as will appear from the 

 distinctions of the sections enumerated further on. Differing as these 

 do from each other, they are all distinguished from their nearest allies, 

 Malvaceae, by their 2-celled anthers, and from Tiliaceoe and Elaeocarpeae by 

 their monadelphous stamens. Their valvate calyx is the great mark of com- 

 bination which unites them with these last-mentioned orders. The fruit 

 of Sterculia often exhibits beautiful illustrations of the real nature of that 

 form of fruit which botanists call the follicle, and helps to demonstrate that 

 it, and hence all simple carpella, are formed of leaves, the sides of which 

 are inflexed, and the margins dilated into placentae, bearing ovula. In Ster- 

 culia platanifolia, in particular, the follicles burst and acquire the form of 

 coriaceous' leaves, bearing the seeds upon their margin. But, notwith- 

 standing this peculiarity of the distinct carpella, on account of which 

 Sterculia would, as the type of an order, be referable to another artificial 

 section, it is impossible to doubt that Reevesia, a remarkable Chinese 

 plant, having the habit and peculiar conformation of anthers found in Ster- 

 culia, along with the petals and fruit of Pterospermum, completely identifies 

 the genus with polypetalous syncarpous orders. 



The following are the sections : — 



§ 1. True Sterculiacex. 



Biittneriaceae, § Sterculiaceae, Kunth, 1. c. (1822). § Sterculieae, Dec. 

 Prodr. 1. 481.(1824.) 



Flowers frequently unisexual. Flowers with or without petals. Sta- 

 mens often connected in a long column, bearing the anthers at the apex. 

 Fruit either deeply lobed, or concrete. — Trees. Leaves simple, entire, or 

 lobed ; petioles with a swelling at both their base and apex. 



Examples. Sterculia, Heritiera, Reevesia. 



§ 2. DOBIBEYACE^. 



Biittneriaceae, § Dombeyaceac, Kunth, 1. c. (1822). Dec. 1. c. (1824.) 

 Calyx 5-lobed. Petals 5, rather large, unequal -sided, convolute in 

 aestivation. Stamens some multiple of the number of tlie petals, in a 

 single row, monadelphous, rarely all fertile, usually some sterile, thread- 

 er strap-shaped ; some (usually 2 or 3 between each sterile stamen) fertile, 

 and more or less combined. Styles from 3 to 5, combined or distinct. 



