606 



TREES OF NORTH AMERICA 



inner surface, rudimentary or in the sterile flower; ovules numerous, suspended from the 

 angle opposite the posterior petals. Legume oblong, subfalcate, turgid or slightly com- 

 pressed, several-seeded, 2-valved, tardily dehiscent, the thin tough woody valves thick- 

 ened on the margins into narrow wings, pulpy between the seeds. Seeds ovoid or slightly 

 obovoid, suspended by a long slender funicle; seed-coat thick, bony, brown and opaque, 

 of 3 layers; embryo surrounded by a thin layer of horny albumen; cotyledons ovate, 

 orange-colored, thick and fleshy, the radicle short, erect. 



Gymnocladus, with two species, is confined to eastern North America and to central 

 China. 



Gymnocladus is slightly astringent and purgative, and the detersive pulp surrounding 

 the seeds of the Asiatic species is used in China as a substitute for soap. 



The generic name, from yv/j.v6s and K\d8os> relates to the stout branchlets destitute 

 of spray. 



1. Gymnocladus dioicus K. Koch. Kentucky Coffee-tree. Mahogany. 



Leaves l-3 long, 18'-24' wide, obovate, 5-9 pinnate, the pinnse 6-14-foliolate, covered 

 when they unfold with hoary tomentum except on the upper surface of the ovate acute 



Fig. 556 



leaflets, often mucronate, especially while young, cuneate or irregularly rounded at base, 

 pink at first, soon becoming bronze-green and lustrous, glabrous on the upper surface 

 with the exception of a few scattered hairs along the midrib, and at maturity thin, ob- 

 scurely veined, dark green above, pale yellow-green and glabrous below, with the ex- 

 ception of a few short hairs scattered along the narrow midrib, 2'-2' long and 1' wide, or 

 those replacing the lowest or occasionally the 2 lower pairs of pinnae sometimes twice ;is 

 large; turning bright clear yellow in the autumn before falling; petioles abruptly and con- 

 spicuously enlarged at base, at first hoary-tomentose, becoming glabrous at maturity; 

 stipules lanceolate or slightly obovate, glandular-serrate toward the apex, 3 ' long. Flowers: 

 inflorescence of the staminate tree 3 '-4' long, the lower branches usually 3 or 4-flowered; 

 inflorescence of the pistillate tree 10'- 12' long, the flowers on stout pedicels l'-2^' long or 

 twice to five times as long as those of the staminate flowers; flowers hoary-tomentose in the 

 bud; calyx f ' long, covered on the outer surface when the flowers open with pale hairs and 

 on the inner surface with hoary tomentum; petals keeled, pilose on the back, slightly 

 grooved, tomentose on the inner surface; anthers bright orange color; ovary hairy. Fruit 

 6'-10' long, l'-2' wide, dark red-brown, covered with a glaucous bloom, on stout stalks 

 l'-2' in length, remaining unopened on the branches through the winter; seeds sep- 

 arated by a thick layer of dark-colored sweet pulp, f ' long. 



