SAXIFRAGACEM. 399 



eight free carpels, superposed and slightly adherent to the base of 

 the sepals, and each consisting of a free one-celled ovary ; this tapers 

 above into a recurved style, traversed by a ventral groove with 

 stigmatiferous lips. In each overy is inserted near the apex of the 

 ventral angle a descending ovule, 1 orthotropous or nearly so, with its 

 micropyle downwards. 2 The fruit, borne on a spherical pedunculate 

 receptacle, consists of a large number of elongated obpyramidal 

 achenes, surrounding at the base by a fringe of long rigid hairs, 

 and surmounted by the persistent style. Each achene contains a 

 descending seed, 3 whose thin coats cover a fleshy albumen, 4 sur- 

 rounding an axile embryo, with an inferior cylindro-conoidal radicle, 

 and oblong cotyledons often unequal (fig. 481). The Planes are 

 usually lofty trees, natives of North America and Mediterrannean 

 Asia. The bark often peels off in plates of variable size and colour. 8 

 Their leaves are alternate, palmiveined and palmilobate, 6 covered with 

 stellate down when young. The base of the petiole is swollen, and 

 hollowed into a conical cavity which long envelopes 7 the axillary bud. 

 It is accompanied by two lateral stipules, which unite below into a 

 tube embracing the branch above the insertion of the leaves, and 

 expands higher up into a more or less irregular cornet, with a dentate 

 margin ; above the stipules become quite detached to a variable 

 extent. 8 The flowers are vernal ; and the unisexual inflorescences are 

 solitary, or grouped in a string, a few together and sessile, on a 

 common pendant axis ending a young shoot. As many as half a 

 score species have been made, 9 which may, no doubt, be reduced to 

 two or three. 1 " 



1 There are said to be sometimes two. aud inside the cone formed by the dilated petiole 



2 Often it rises up a little, instead of being a narrow opening into the cavity occupied by the 

 quite inferior, the major axis of the ovule being bud, which proves that this is a groove in the 

 slightly curved, as though through an attempt upper surface of the petiole, whose lips have risen 

 at anatropy. The ovule has two coats. up and approached one another above the primi- 



3 Very frequently sterile in the trees culti- tively free bud. The latter becomes visible and 

 vated in Europe. quite free at the fall of the leaf. 



4 Some authors describe it as very thin ; the 8 They generally separate from one another, 

 majority say there is none. especially on the side next the petiole. 



5 This exfoliation depends on the form of the 9 Dttham., Arbr., ed. nov. ii. 7, t. 2. — Ntjtt., 

 plates of periderm that form large islands, dis- Suppl. to the N.- Am. Sylv.,\. 47, 1. 15. — Catesb., 

 tributed between the suberous layers, and which Carol., i. t. 56. — Moeic., in Bull. Terr. Bot. 

 soon come away, carrying with them the adjacent (1830), 79; PI. Nouv. Amir. (1833), 39, t. 26. — 

 suberous layers. Hook. & Abn., in Beech. Voy., Bot., 160, 390. — 



6 " Margins of the blade longitudinally plicate Maet. & Gal., in Bull. Acad. Brux., x. n. 4, 

 externally in vernation." (Doll., 2 EM. Laubkn. p. 2. — Benth., Voy. Sulph., Bot.,54; PI. Hart- 

 Ament., fig. 4.) weg., n. 1961.— Geen. & Gode., Fl. de Fr„ ill. 



" Not totally, as would appear at first sight, 145. 

 for even when adult we may always find above 10 Before the discovery of the recently described 



