PLATANACEAE. 163 



Family 6. PLATANACEAE Lindl. 



Plane-tree Family. 



Large trees, with alternate petioled palraately lobed and veined leaves, 

 the hollowed petiole-bases enclosing- the buds for the following season, the 

 bark exfoliating, and small green monoeoious flowers in dense globular 

 heads. Receptacle somewhat fleshy. Calyx of 3-8 externally pubescent 

 minute sepals. Corolla of as many thin glabrous petals. Staminate 

 flowers with stamens as many as the sepals and opposite them; filaments 

 short; anthers oblong or linear, longitudinally dehiscent. Pistillate flowers 

 with 2-8 distinct pistils; ovary linear, 1-celled; style elongated; stigma 

 lateral. Ripened head of fruit composed of very numerous narrowly 

 obpyramidal nutlets which are densely pubescent below with long nearly 

 erect hairs. Seed pendulous; endosperm thin; cotyledons linear. Only 

 the genus Platanus, comprising some 7 species, natives of the north tem- 

 perate zone. 



Platanus acerifolia Willd., London Plane, said to be of hybrid origin, is 

 commonly planted for shade and ornament and becomes as large as any tree 

 grown; its fruiting pendulous flower-cluster consists of 1, 2 or 3 globular dense 

 heads; its sharply lobed leaves are 6' or 8' wide. It has been confused with 

 P. orientalis L., which is supposed to be one of its parents and the American 

 Plane the other. 



Platanus occidentalis L., American Plane, North American, is recorded 

 by Reade, by H. B. Small, and by Lefroy as grown in Bermuda. Its fruiting 

 flower-cluster consists of one globular head. 



Family 7. ROSACEAE B. Juss. 



Rose Family. 



Herbs, shrubs, or trees, with alternate (in some few genera oppo- 

 site) leaves, and regular perfect or rarely polygamo-dioecious flowers. 

 Stipules commonly present, sometimes large. Calyx free from or adnate 

 to the ovary, 5-lobed (rarely 4-9-lobed), often bracteolate. Disk adnate 

 to the base of the calyx. Petals equal in number to the calyx-lobes, dis- 

 tinct, or none. Stamens usually numerous, distinct ; anthers small, 2-celled. 

 Carpels l-oo, distinct, or adnate to the calyx. Ovary 1-celled or rarely 

 imperfectly 2-celled; style terminal or lateral. Ovules 1, 2, or several, 

 anatropous. Fruit mostly follicles or achenes; endosperm none, or rarely 

 copious. About 75 genera and more than 1200 species, of wide geograjihic 

 distribution. 



Style lateraL 1. Durh</<nea. 



Style terminal. 2. PotvtitiUa. 



1. DUCHESNEA J. E. Smith. 



Perennial herbs, with leafy runners, 3-foliolate long-petioled leaves and 



axillary slender-peduneled yellow perfect flowers. Calyx 5-parted, 5-bracteolate, 



the bractlets larger than the calyx-segments and alternating with them, dentate 



or incised. Petals 5, obovate. Stamens numerous. Pistils numerous, borne 



on a hemispheric receptacle which greatly enlarges but does not become pulpy 



in fruit. Achenes superficial on the receptacle. [In honor of A. X. Duchesne, 



French botanist.] Two species, natives of southern Asia, the following typical. 



