GENUS 5. 



SENNA FAMILY. 



339 



I. Gleditsia triacanthos L. Honey or Sweet 



Locust. Three-thorned Acacia. Black 



or Thorn Locust. Fig. 2445. 



Gleditsia triacanthos L. Sp. PI. 1056. 1753. 



A large tree, with rough bark, maximum height 

 about 140 and trunk diameter 5*, usually armed 

 with numerous stout branching or simple thorns. 

 Leaves petioled, i-2-pinnate; leaflets short-stalked, 

 oblong-lanceolate or oval, obtuse at each end, in- 

 equilateral at the base, glabrous above, often pubes- 

 cent on the veins beneath, crenulate, 8"-i5" long; 

 racemes solitary or clustered, slender, drooping, 

 dense, 3'-5' long; flowers greenish, about 2" broad; 

 pod linear-oblong, i-ij long, i'-ii' wide, stalked, 

 glabrous and shining, twisted, many-seeded, pulpy 

 within, sometimes eaten. 



In woods, western New York and Ontario to Michi- 

 gan, Georgia, Kansas and Texas. Naturalized and ex- 

 tensively planted further east. Wood durable, bright 

 brownish-red ; weight per cubic foot 42 Ibs. Pulp of 

 the pod-sweet. May-July. Honey. Honey-shucks. Sweet- 

 bean. 



2. Gleditsia aquatica Marsh. Water or Swamp 

 Locust. Fig. 2446. 



Gleditsia aquatica Marsh. Arb. Am. 54. 1785. 

 Gleditsia rnonosperma Walt. FI. Car. 254. 1788. 



A tree, with maximum height of about 60, and 

 trunk diameter of 22, the thorns usually simple. 

 Foliage similar to that of the preceding species, but 

 the leaflets thicker, darker green, usually larger, ovate- 

 lanceolate or lanceolate in outline, the margins more 

 conspicuously crenulate ; racemes drooping, elongated ; 

 pod obliquely oval, flat, glabrous, narrowed at each end, 

 slender-stalked, i'-ii' long, p"-i2" wide, i-seeded, not 

 pulpy within. 



In swamps, Indiana to Missouri, South Carolina, Flor- 

 ida and Texas. Wood very hard, bright reddish-brown ; 

 weight per cubic foot 46 Ibs. July. 



6. GYMNOCLADUS Lam. Encycl. i : 733. 1783. 



Trees, with bipinnate leaves, and showy white dioecious or polygamous flowers in ter- 

 minal racemes. Calyx tubular, 5-lobed, the lobes narrow, nearly equal. Petals 5 (rarely 4), 

 oblong or oval, nearly equal, imbricated, inserted at the top of the calyx-tube. Stamens 10, 

 distinct, shorter than the petals and inserted with them; filaments pubescent; anthers all 

 alike, longitudinally dehiscent. Ovary rudimentary, or none in the staminate flowers, sessile 

 and many-ovuled in the pistillate and polygamous ones; style straight. Pod oblong, thick, 

 large, coriaceous, flat, pulpy between the seeds, 2-valved. [Greek, naked-branch.] 



A monotypic genus of eastern North America. 



