332 TREES OF NORTH AMERICA 



early summer; calyx 4-lobed, the lobes imbricated in sestivation; the staminate long- 

 pedicellate, in short or ultimately elongated racemes borne on long slender drooping pe- 

 duncles from the axils of crowded leaves on the spur-like branchlets of the previous year; 

 calyx ovoid, gradually narrowed into the slender pubescent pedicel, coated on the outer 

 surface with pale hairs, divided to the middle into equal acute boat-shaped lobes; stamens 

 4, inserted opposite the lobes of the calyx on the margins of the minute thin pulvinate disk; 

 filaments flattened, light green, glabrous, infolded above the middle in the bud, with the 

 anthers inverted and back to back, straightening abruptly in anthesis and becoming ex- 

 serted; anthers oblong, attached on the back near the middle, introrse, 2-celled, the cells 

 attached laterally to a minute oblong or semiorbicular connective, free and spreading above 

 and below, opening by longitudinal lateral slits; pistillate sessile in dense globose many- 

 flowered heads on short stout peduncles axillary on shoots of the year; calyx ovoid, divided 

 to the base into oblong thick concave lobes, rounded, thickened, and covered with pale hairs 

 at the apex, longer than the ovary and closely investing it, the 2 outer lobes much broader 

 than the others, persistent and inclosing the fruit; ovary ovoid, compressed, sessile, green, 

 and glabrous; style covered by elongated slender filiform white stigmatic hairs; ovule sus- 

 pended from the apex of the cell, anatropous. Drupes oblong, compressed, rounded and 

 often notched at apex, acute at base, with thin succulent flesh, and a thin crustaceous 

 light brown nutlet, joined by the union of the thickened and much elongated perianths of 

 the flowers into a globose compound fruit saturated with milky juice, mammillate on the 

 surface by their thickened rounded summits, light yellow-green, usually of full size but 

 seedless on isolated pistillate individuals. Seed oblong, compressed, rounded at base, ob- 

 lique and marked at apex by the conspicuous oblong pale hilum, without albumen ; seed- 

 coat membranaceous, light chestnut-brown; embryo recurved; cotyledons oblong, nearly 

 equal; radicle elongated, incumbent, ascending. 



The genus is represented by a single species of eastern North America. 



The generic name is in compliment to William Maclure, distinguished geologist. 



1. Madura pomifera Schn. Osage Orange. Bow Wood. 



Toxylon (loxylon) pomiferum Rafn. 



Leaves 3'-5' long, 2'-3' wide; turning bright clear yellow before falling in the autumn; 

 petioles l|'-2' in length. Flowers: racemes of the staminate flowers I'-l?' long; heads 



Fig. 302 



of the pistillate flowers, f '-!' in diameter. Fruit 4'-5 / in diameter, ripening in the autumn, 

 and soon falling to the ground. 



