GLEDITSIA AQUATICA Marshall. Water Honey Locust. (× 1/2.)
2. Gleditsia aquática Marshall. Water Honey Locust. [Plate 107.] A medium sized tree with rather smooth bark, which becomes rough and flaky on large trees; twigs greenish, turning to a light brown by the end of the year; branchlets a greenish-gray brown; spines all usually more or less flattened, those of the branchlets and branches, rather few and usually simple, 4-10 cm. long, those of the trunk branched, spines do not develop on the year's growth; leaves from old wood pinnate, from the year's growth bipinnate; rachis grooved and pubescent or puberulent above and smooth below; leaflets generally 7-11 pairs, variable in shape and size, generally lanceolate and 1.5-2.5 cm. long, on petiolules about 1 mm. long, glabrous; flowers similar to the preceding species; fruit a glabrous, shining, oblique pod about 4-5 cm. long, containing 1 seed; seeds orbicular, flat, chestnut brown, about 1 cm. in diameter.
Distribution.—Atlantic Coast from North Carolina south to Florida, and the Mississippi Valley from southwestern Indiana southward to Texas. In Indiana this species is rare and limited to the banks of river sloughs, locally called ponds and to one cypress swamp. It is known to have occurred on the banks of Wabash and Dan's ponds and Little Cypress swamp in the southwest corner of Knox County, and in Gibson County on the bank of a slough near Skelton and about Burnett's pond. The reference to Posey County is without a verifying specimen, although it may be found in the county. The writer has visited about every place in the county where the species might occur, and has never found it. Gorby's[57] reference for Miami County is without doubt an error. In our area it is a low crooked tree and grows with its base submerged more or less during the year. The idea of the proportions of this tree can be obtained from the measurements taken from the largest tree now known in Indiana, which is located on the shore of Dan's pond in Knox County. It measures 158 cm. (66 inches) in circumference at 1 m. above the ground, and is estimated to be 10 m. (30 feet) high. This species is too rare to be of economic importance.
Gleditsia aquatica × triacanthos. Dr. Schneck[58] found two honey locust trees which he described as hybrids of the two species. The one was located on the bank of Dan's pond in Knox County, and the other in Gibson County. The original description is as follows: "In both instances the pods are the distinguishing feature. These are very much alike in both trees, being about 5 inches long, 11/2 inches wide, smooth, shining, of a light brown color and entirely destitute of pulp. Otherwise the tree cannot be distinguished from the trees among which they stand. They are both about 50 feet high, with short stems and spreading branches, and stand about 5 miles apart." The writer has five fruiting specimens from these two trees, taken by Dr. Schneck. Two of the sheets have the round and branched spines of G. triacanthos.