447 



HUMIRIACEiE. 



[Hypogynous Exogens. 



Mr. Miers is of opinion that one of the character.? which particularly distinguish 

 this family, " proves its affinity with the Styracese, and brings it within the scope 

 of his alliance of the Cionospermefe, where the ovules are always suspended from 

 the summit of a free central placenta. Although the five cells are here estab- 

 lished throughout the entire length of the ovarium, still, for a short distance 

 near the apex, there exists a communication between all the cells, through small 

 chinks round the margins of the apical portions of the dissepiments, showing that 

 they are incomplete, and fail in reaching the central placentary column, which is 

 here free from them and from the style, a fact explanatory of the meaning of 

 A. Jussieu : " loculis ad apicem inter se perviis." As in Styracese, the ovules are 

 suspended in two series, some being thus ascending, others pendulous ; and hence, in 

 their development, the seeds will be found to be sometimes erect, often inverted, but 

 in all cases the radicle points to the hilum. In this family we perceive an ovarium 

 perfectly free, supported on a distinct gynophorus, and surrounded at its base by a 

 conspicuous cupuliform ring toothed on its margin, but perfectly free on both surfaces 

 to the base ; the ovarium is hairy on all parts except those enveloped by that cup, 

 which nowhere adheres either to it3 glabrous portion, or to the gynophorus. 

 Outside of this hypogynous cup is seen another cup-shaped ring, serving to support 

 the stamens, which in H. floribundum is entire, smooth, and fleshy outside, and bears 

 the many series of filaments upon its margin, as well as on the whole of its inner 

 surface, forming thus a second annular ring, free both from the hypogynous cup and 

 the petals. Here, therefore, we perceive the gynophorus, the ovarium, cupuliform 

 disk, staminiferous cup, petals, and sepals, each a distinct development, and each free 

 to the base, but all springing from a fleshy torus, which is simply an expansion of the 

 apex of the pedicel. The torus, therefore, as an organ well marked in many of the 

 Thalamiflorse, must not be confounded with any of the distinct developments it serves 

 to support." 



Mr. Miers also proposes the following new Natural Order. 



"APTANDRACEJE. 

 Aptandracese, Miers, Ann. Nat. Hist. 2nd Ser. 1. p. 200. (1851); Contrib. Bot. 1. p. 1. 

 " Trees with alternate, petiolated, entire leaves, without stipules, and slender axillary 

 branching panicles of minute pedicelled flowers, sub-umbellately aggregated. Calyx 



very small, patelliform, 

 4-toothed, persistent, and 

 increasing with the growth 

 of the fruit. Petals 4, 

 equal, linear, free, revolute, 

 inflected at apex, and val- 

 vate in aestivation : 4 small 

 petaloid scales, alternate 

 with them, and placed be- 

 tween them and the sta- 

 minal tube. Stamens co- 

 hering into a fleshy tube, 

 nearly as long as the petals, 

 with 8 equal anther-lobes, 

 externally adnate in a close 

 ring around its thickened 

 mouth, and opening ex- 

 trorsely by a valve-like 

 membrane hinged at the 

 bottom and reflected : pol- 

 len singularly cruciform. 

 Ovary quite free, com- 

 pressed, and 2-grooved, sup- 

 ported on a stipitate gyno- 

 phorus, 1-locular at the 

 summit, 2-locular at base, 

 with a single anatropal 

 ovule in each incomplete 

 cell, suspended from near 

 the apex of a free central 



Fig. CCCX. bis. 



Fig. CCCX. bis. — Aptandra Spruceana. 1. au expanded flower; 2. a petal; 3. tube of stamens, 

 with 4 petaloid glands at the base ; i. pistil ; 5. section of ovary— from drawings by Mr. Miers. 



