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 s4°, usually armed 

 with numerous stout branching or simple thorns. 

 Leaves petioled, 1-2-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"-is" long; 

 racemes solitary or clustered, slender, drooping, 

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

 pod linear-oblong, i°-ii° 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 lbs. Pulp of 

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

 bean. 



2. Gleditsia aquatica iMarsh. Water or Swamp 

 Locust. Fig. 2446. 



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



Gleditsia tnonosperma 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, 9"-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 lbs. 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 S (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. 



