ptl 



NATURAL HISTORY OF PLANTS. 



carpels, each superposed to a petal,' which appear to cohere for a certain 

 distance along the inner angle, where each ovary contains a vertical 

 placenta bearing two parallel rows of ascending anatropous ovules ; 



the micropyle looks downwards and inwards. 

 The plant is frutescent, and gives off' linear 

 exstipulate leaves. The flowers are terminal, 

 and usually solitary. 



In certain species of Plenrandra, the sta- 

 mens nearest the perianth are reduced to 

 starainodes -^ and in others, which offer a 

 good transition between these and the c}'- 

 clandrous Hibbertia, there are not only 

 staminodes intermixed with the fertile sta- 

 mens,^ but on the other side of the orv- 

 n.Tceum, whose orcranization remains unaltered are some of these 

 sterile filaments which never become fertile.' Now so niT- 

 merous are the transitions between the species of Hibbertia which 

 possess a circular and perfect androceum, and those which possess 

 unilateral stamens, either all fertile or all sterile, that after 

 studying all the species it appears impossible to split them up into 

 sufficiently distinct generic groups.^ 



llihheriia angustifolia. 

 Fig. 139. 

 Diagram. 



' We have observed {J.oc. cit.) how the 

 gynajceum first appears as two carpellary leaves 

 sui)erposcd to the petals which alternate with sepal 

 5, and how the apparently alternipetalous dis- 

 sepiment is formed merely hy the floral axis 

 drawn out into a wedge and receiving the inser- 

 tion of the bases of the carpellary leaves on its 

 very oblicjue faces. 



' This occurs not only in Pletirandra pro- 

 perly so called, but also in Hemistemma (ex. 

 DC, Sy.i(., i. 412; Prodr. i. 71; Deless., 

 Icon., t. 71-77; — ExDL., Gen., n. 4757; — 

 Walp., .4m?!., i. IG, some of which are Ocea- 

 nian, while others come from Madagascar — 

 the latter often possessing opposite or nearly 

 opiwsite leaves. They were collected and studied 

 for the first time by Commkrson and by 

 NoRONiiA, who, according to Dui'ETIT-Tiiouaes 

 (Oe7i. Madafiasc, 18). gave them the name 

 A;iUijn. In H. Cotnmerxonii DC, there are 

 flowers without sterile stamens. P^ach carpel 

 contains two ovules. Tiie gynmceum is the 

 same in II. dealhala R. Be., where the insertion 

 of the styles is much bent outwards. The fertile 

 stamens have long erect linear introrse anthers, 

 the external staminodes are much shorter. On 



Hemistemma, see also Hook. F., HooJc. Journ. x. 

 48 ; and F. Mtieller, Fragm. i. 151. This last 

 observer has also clearly shown that species like 

 H. spicata serve as a passage between Pleurandra 

 and Hemistemma {Frarim. ii. 1). 



** Hemipleurandra Benth. & Hook. (loc. cit.). 

 " Stamina unilateralia ; staminodia ad utrumque 

 lalus staminum sit a v. in tota j)('ri]}heria. In 

 Hemistepho Dettmm. & Haev. {Hook. Jonrn., 

 vii. 51) peduncidi unilateraliter cc-Jlori et 

 staminodia nonnuUa eiiam, sub staminiius oh- 

 servantv.r." Hemistephus linearis Deumm. & 

 Haey. was to F. Muellee Hemistemma lineare 

 {Fragm., i. 162). The same author has proposed 

 a section Dipleurandra for his H. asperifolia. 



•* In H. angustifolia Benth. {Ft. Austr., i. 

 21), the diagram of which is given in fig. 139, 

 we often see two bundles of fertile stamens, with 

 a bundle of staminodes between them — one on 

 each side, and a fourth the other side of the 

 gynasceum. 



* " Genus e stamimtm indole commode in 

 sectiones 4 dividifur, quarum twnmdlcB ah auc- 

 torilus pro generihus Jiahentur. Nimis iamen 

 artificiales sunt, nee habitu consonant." (B. H., 

 loc. cit.) 



