556 TREES OF NORTH AMERICA 



from the base to the apex of the leaf, the lowest sometimes reduced to single 

 leaflets, deciduous; stipules minute, caducous; leaflets membranaceous, their mar- 

 gins irregularly crenate, without stipels. Flowers regular, polygamous, minute, 

 green or white on short pedicels, in axillary or lateral simple or fascicled racemes, 

 with minute scale-like caducous bracts; calyx campanulate, lined with the disk, 

 3-5-lobed, the narrow lobes nearly equal; petals as many as the lobes of the calyx, 

 nearly equal; stamens 6-10, inserted with the petals on the margin of the disk, 

 exserted; filaments free, filiform, erect; anthers uniform, much smaller and abor- 

 ti^e in the pistillate flower; ovary subsessile, rarely bicarpellary, rudimentary or 

 in the staminate flower; styles short; stigma terminal, more or less dilated, 

 often oblique; ovules 2 or many, suspended from the angle opposite the posterior 

 petal. Legume compressed, many-seeded, elongated, straight and indehiscent, or 1 

 or 2-seeded, ovate and tardily dehiscent. Seeds transverse, ovate to suborbicular, 

 flattened, attached by long slender funicles; seed-coat thin, crustaceous, light brown; 

 embryo surrounded by a layer of horny albumen, orange-colored; cotyledons sub- 

 foliaceous, compressed; radicle short, erect, slightly exserted. 



Gleditsia is confined to eastern North America, where three species occur, south- 

 western Asia, China, Japan, and west tropical Africa. It produces strong, durable, 

 coarse-grained wood. In Japan the pods are used as a substitute for soap. 



The generic name is in honor of Johaun Gottlieb Gleditsch (1714-1786), professor 

 of botany at Berlin. 



CONSPECTUS OF THE NORTH AMERICAN ARBORESCENT SPECIES. 



Legume linear-oblong, elongated, many-seeded, indehiscent. 



Legumes 12'-18' long, with pulp between the seeds ; ovary hoary-tomentose. 



1. G. triacanthos (A, C). 



Legumes 4'-5' long, without pulp between the seeds. 2. G. Texana (C). 



Legume oval, oblique, 1 or 2-seeded, without pulp, tardily dehiscent ; ovary glabrous. 



3. G. aquatica (C). 



1. Gleditsia triacanthos, L. Honey Locust. 



Leaves 7'-8' long, 18-28-foliolulate or sometimes bipinnate, with 4-7 pairs of 

 pinnae, those of the upper pair 4' 5' long, when they unfold hoary-tomentose, and at 

 maturity pubescent on the petioles and rachises, the short stout petiolules, and the 

 under surface of the midribs of the leaflets, turning in the autumn pale clear yellow; 

 leaflets lanceolate-oblong, unequal at the base, acute or slightly rounded ,at the apex, 

 remotely crenulate-serrate, dark green and lustrous above, dull yellow-green below, 

 l'-l^' long and ' wide. Flowers appearing in June when the leaves are nearly 

 fully grown from the axils of leaves of previous years; staminate in short many- 

 flowered pubescent racemes 2'-2' long and often clustered; pistillate in slender 

 graceful few-flowered usually solitary racemes 2'-3^' long; calyx campauulate, 

 narrowed at the base, the acute lobes thickened, revolute and ciliate on the margins, 

 villose with pale hairs, rather shorter than and half as wide as the erect acute petals; 

 filaments pilose toward the base; anthers green; pistil rarely of 2 carpels, hoary- 

 tomentose. Fruit 12'-18' long, dark brown, pilose and slightly falcate, with 

 straight thickened margins, 2 or 3 together in short racemes on stalks I'-l^' long, 

 their walls thin and tough, contracting in drying by a number of corkscrew twists, 

 and falling late in the autumn or early in winter; seeds oval, ' long, separated by 

 thick succulent pulp. 



