100 



SILVA OF NORTE AMERICA. 



platanace-;e. 



peduncle ; the sterile heads dark red on axillary peduncles ; the fertile heads light green tinged with 

 red on longer terminal peduncles, the lateral heads in the spicate clusters sessile and embracing the 



peduncle at maturity, usually persistent on the branches during the winter. 



Calyx of the staminate 



flower divided into three to six minute scale-like sepals slightly united at the base, about half as long as 



the three to six cuneiform 



scarious pointed petal 



Sta 



mens as 



any 



the di\ 



of the 



calyx and opposite them ; filaments short or nearly obsolete ; anthers elongated, clavate, two-celled, the 

 cells opening throughout their length by lateral slits, crowned by capitate pilose truncate connectives. 

 Calyx of the pistillate flower divided into three to six, usually into four, rounded sepals much shorter 

 than the acute petals. Staminodia scale-like, elongated-obovate, pilose at the apex. Ovaries as many as 

 the divisions of the calyx, superior, sessile, ovate-oblong, surrounded at the base by long ridged jointed 

 pale hairs persistent around the fruit, gradually narrowed into long simple styles slightly dilated and 

 excurved toward the apex, bright red, papillose-stigmatic to below the middle along the ventral suture ; 

 ovules one or rarely two, suspended lateraUy, orthotropous, covered with two coats. Akene elongated- 

 obovate, rounded and obtuse or acute at the apex, crowned with the remnants of the persistent style, 

 one-seeded, light yellow-brown ; pericarp thin, coriaceous. Seed elongated-oblong, suspended ; testa 

 thin and firm, light chestnut-brown. Embryo erect in thin fleshy albumen ; cotyledons oblong, about 

 as long as the elongated cylindrical erect radicle turned toward the minute apical hilum.^ 



Platanus is now confined to temperate North America, where three species occur, to Mexico, south- 

 western Europe, Asia Minor, Persia, Afghanistan, and northwestern India. It flourished over a larger 



and played a most important part 



forests of the northern hemisph 



d 



and the tertiary periods, when it inhabited Greenland and Arctic America 



ig 

 for 



the late 



m 



hardly 



distinguishable from the 



t> 



species 



of 



North America and Europe, and then, spreading 



southward, was not driven from central Europe until the close of the tertiary period, during which it 

 also inhabited with several species the mid-continental region of North America, from whence it has now 

 entirely disappeared.^ The genus is homorphous, and the six or seven species which are distinguished 

 all resemble each other except in the form of the lobes of the leaves, in the amount of the pubescence 

 on their lower surface, in the obtuse or pointed apex of the akene, and in the number of heads of 

 flowers on the pistiUate peduncles, which vary, however, in the same species. 



Platanus produces hard and heavy, although not strong, light brown wood tinged with red, and 

 containing numerous broad conspicuous medullary rays and bands of small ducts marking the layers of 

 annual growth. The genus is not known to possess useful properties. 



In southern and western Europe, Asia Minor, Abyssinia, northwestern India, and the United 

 States, Platanus orientalist is frequently planted as a shade-tree in streets, avenues, and parks; 



grows 



1 Clarke, Ann, §- Mag. Nat. Hist. ser. 3, i. 102, t. 6, f. 9-13. — Platanus orientalis, of which several varieties are distinguished 



Schoenland, Bot. Jahrb. iv. 308. 



^ Lesquereux, U. S. Geolog. Surv. vii. 181, t. 25-27 ; viii. 44, t. and peninsula to Afghanistan and Cashmere, and now occasionally 

 3, f. 1, t. 7, f. 5, 249, t. 56, f. 4, t. 57, f. 1-2 (Contrib. Foss. FL spontaneously in southwestern Europe, where it was carried by the 

 Western Territories^ ii., iii.) ; Mem. Mus. Comp. Zool. vi. pt. ii. 13, Romans, who shared with the ancient Greeks and Persians their 

 t. 7, f. 12, t. 10, f, 4, 5 (Fossil Plants of the Auriferous Gravel Be- veneration for this tree, with which they formed their groves and 

 yosits of the Sierra Nevada). — L. F. Ward, Gth Annual Rep. U. S. shaded their dwellings. (See Evelyn, Sylva, ed. Hunter, ii. 53. 

 Geolog. Surv. 1884-85, 552, t, 40, f. 8, 9, t. 41 (Syn. Ft. Laramie Loudon, Arh. Brit. iv. 2033.) It is commonly planted as a shade- 

 Group). — Saporta, Origine Paleontologique des Arhres^ 195. — Zit- tree in the valleys of the northwestern Himalayas (Brandis, Forest 

 tel, Handh. Palceontolog. ii. 627, f. 343. — Jank6, Bot. Jahrb. xi. Fl. Brit. Ind. 434), in Persia (Fraser, Historical and Descriptive 



451. 



of 



3 Linnaeus, Spec. 999 (1753). — Pallas, FL Ross. i. pt. ii. 1, t. used more generally than any other tree to adorn city streets and 



51. — No 



Watson 



Flore ForestierCy ed. 3, 373), and occasionally 



101, — Sibthorp, FL Grcec. x. 36, t. 945. — A. de Candolle, Prodr. the middle and north Atlantic United States, where the Oriental 

 xvi. pt. ii. 159. — Parlatore, FL ItaL iv. 373. — Bommer, Les Pla- Plane is hardy as far north as Massachusetts. The wood is used 

 tanes et leur Culture^ 10. — Boissier, FL Orient, iv. 1161. — Jankd, in Persia and other countries of western Asia for furniture 



and 



449 



Hooker f. FL Brit. Ind. v. 594. 



the construction of houses, and it is made into trays and other 

 Platanus vulgaris^ Spach, Ann. ScL Nat. s6t. 2, xv. 291 (excl. small articles of domestic use (Gamble, Man. Indian Timbers, 345). 

 angulosa) (1841). 



