With the brambles, the following few species are the only thorny or prickly woody plants with compound leaves (whether alternate or opposite). The only other upright thorny plants are those with simple leaves on Plates 37-40. The locusts and Trifoliate Orange have smooth-edged or fine-toothed leaflets whose leafstalks never bear thorns; the other plants of this group have more coarsely toothed leaflets and often thorny leafstalks,
HONEY LOCUST Gleditsia triacanthos L. pp. 12, 152
Recognition: A tall tree with feather-compound or twice-compound leaves. Bark dark, somewhat scaly, adorned with numerous stout branched thorns, each several inches long. Leaves
IV, THORNY TREES AND SHRUBS
divided into numerous narrow leaflets, which may be slightly toothed, These leaflets, in turn, frequently are subdivided Hairless buds, hidden by the leafstalk bases in summer, are surrounded by leaf scars when twigs are leafless and may be supplemented by smaller buds located just above them. End buds false, wigs stout; bundle scars 3, Leaves 15". Height 70'-80' (140'); diameter 2'-3' (6'). Flowers small, greenish, clustered May-Julv. Fruits 8"-18" long* flattened twisted pods with sweet pulp between numerous oval seeds, Sept-Feb. Similar species: (1) Only Water Locust also has such long thorns, (2) Black Locust has small paired thorns. Remarks: Honey Locust, believed originally to have been restricted to Mississippi Valley, is now common eastward. The thorns have been used by woodsmen for pins, spear points, and animal traps. Heavy, durable wood used tor railroad ties, fence posts, and agricultural implements. The tree does not harbor root bacteria capable of fixing nitrogen as do most legumes. Fruits eaten by cattle, deer, rabbits, squirrels, and bobwhite. A thornless varietv is sometimes cultivated.
WATER LOCUST Thorn illus., p. 152
Recognition: Similar to Honey Locust but smaller, with leaflets somewhat wider, thorns of branches niostlv unbrariched and fruit pods only 2" long, pulpless, containing only 1-3 seeds. Coastal Plain swamps; e. N. Carolina to centr. Florida, west to e. lexas, and north in the Mississippi Valley to sw, Indiana, s, Illinois, and se, Missouri.
BLACK LOCUST Robinia pseudo-acacia L, pp. 12, 152
Recognition: V medium-sized tree with once-compound leaves. Leaflets 6-20, egg-shaped. Strong W'-V paired thorns flank nearly circular leaf scars. White-hairy buds burst through leaf scars upon enlargement. Twigs moderately stout, hairless;
bundle scars 3, End buds false, bark on old trunks dark, deeply ridged, and crosshatched. Leaves 6"-12" Height 70'-S0' (100'); diameter 2'-3' (6'). Flowers medium-sized, white, clustered, fragrant, May-June. Fruits 2"-6" long, flat pods, Sept.-April.
Similar species; Other Robinia locusts have bristly, glandular or hairy twigs, (1) Prickly-ash is smaller and has reddish exposed buds, toothed leaflets, and usually thorny leafstalks. (2) Honey Locust has large branched unpaired thorns. Remarks: Black Locusts often planted for fence posts- Wood strong, hard, and durable in the soil. Young shoots and bark sometimes poisonous to livestock but seeds eaten by bobwhite, pheasant, mourning dove, cottontail rabbit, snowshoe hare, and deer.
IV. THORNY TREES AND SHRUBS
CLAMMY LOCt'ST Robinia vuscam Vent. Twig ilJus., p. 152
Recognition: A shrub or small tree; leaves similar to Black Locust. Thorns paired, weak, usually not over Vi"; twigs covered with sticky glands. Bark smooth, light brown, marked with short horizontal streaks. Leaves ft"-12". Height 5-20'(40'); diameter l"-3" (6"). Flowers pink, not fragrant. May. Fruits sticky pods, 2"-3'\ Aug.-Sept Mountain woods; Pennsylvania and \V. Virginia to Georgia and Alabama; occasionally escaped from cultivation northward to Nova Scotia and Quebec-
BRISTLY LOCUST Robinia hispida L. Twig illus,, p. 132 Recognition: Similar to Clammy Locust but shrubby and twigs covered with bristly hairs almost as long as the paired thorns. Leaflets bristle-tipped; buds visible in winter. Height 2'-10\ Flowers rose-colored (often culled Rose-acacia), not fragrant,
May-June. Fruits bristly, Sept, Mountains from Virginia and Tennessee to Georgia and Alabama; escaped from cultivation northward to Connecticut
DOWNY LOCUST Not illus.
Robinia elliottii (Chapm.) Ashe
Recognition: Similar to Black Locust but a low shrub with gray-hairy twigs, small thorns, and 5-7 leaflets that are somewhat hairy beneath. Height to 6', Flowers purplish, May. Fruits hairy. Thickets and woods; N« Carolina and Georgia; escaped from cultivation in ne* Maryland.
Recognition: A very spiny shrub or small tree with very large twice- or even thrice-compound leaves. Trunk and twigs stout, with numerous coarse prickles. Leaflets toothed, pointed; leafstalks thorny. Long, narrow leaf scars have about 20 bundle scars. End buck may be false. Leaves 2'-4\ Height 5'-15' (35'); diameter 1-4" (9"). Flowers white, in flat-topped clusters, July-Sept. -Tints black, fleshy, 1-seeded, Aug,-Nov. Similar species: Prickly stout stems and V-shaped leaf scars with numerous bundle scars are distinctive at all seasons. (1) Bristly Sarsaparilla is smaller, bristly rather than prickly, (2) DevilV club (p. 197) has simple leaves and northwestern range.
BRISTLY SARSAPARILLA Twig illus,, p. 152
Recognition: Similar to Hercules-club but smaller and woody only at stem base, with once- or twice-compound leaves. Twigs and leafstalks bristly-hairy. Leaves 4"-12". Height 6"-3B". Flowers June*Aug. Fruits blue-black, Aug,-Sept, Poor soils;
IV. THORNY TREES AND SHRUBS
Newfoundland, s. Labrador, and Manitoba to w, Y Carolina, West Virginia, Illinois, and Minnesota.
Recognition: A shrub, often thicket-forming, with ;utir* d phcklcs Hanking leaf scars and buds. Leaves once-compound with 5-11 toothed egg-shaped leaflets and often prickly leafstalks. Foliage has lemon like odor when crushed and is hairy when young. Buds red-hairy, located above leaf scars. Bundle scars 3- True end m *
buds present. Specimens without prickles are encountered rarely. Leaves 3"-10", Height 4'-10' (25')- Flowers small, greenish, clustered, April-May. Fruits small,dry, reddish-brown, 1- to 2-seeded pods, Aug,-Oct.
Similar species: (1) Black Locust grows to tree size, has hidden buds, leaflets not toothed, leafstalks not prickly, (2) See Southern Prickly-ash,
Remarks: Chewing leaves, fruits, or bark was once popular as a toothache cure. Known as Toothache-tree in some places.
SOUTHERN PRICKLY ASH Leaflet illus,, p. 152
Recognition: This southern shrub or tree is larger than the northern species. Has a peculiar smooth gray trunk bark decorated with scattered targe corky knobs, often prickle-tipped. Leaflets hairless, shinv, somewhat curved and unsymmetrical. Leaves8"-16", Height 10'-20' (50'); diameter4"-8" (18")- Poor Coastal Plain soils; se. Virginia to s. Florida and west to e. Texas, north in Mississippi Valley to s. Arkansas and se. Oklahoma.
Poncirus trifoliata (L.) Raf,
Recognition: An imported shrub often planted as a hed^e in
South. Easily identified by stiff green stems that bear many stout green thorns. Buds bright red, ball-like; end buds false; leaf scars very small, with I scarcely visible bundle scar. Leaves divided into 3 small wavy-edged leaflets. Leafstalks "winged," Small citrus fruits are bitter. Height rarely to 20', Flowers white, April-May. Fruits Sept.-Oct. Thickets; e. Virginia to Florida and Texas,
NORTHERN PRICKLY ASH
IV, THORN LESS TRIFOLIATES
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