388 TREES IN" WINTER 



COMMON LOCUST 

 Black, Yellow or White Locust, Locust, Acacia. 



Robinia Pseudo-Acacia L. 



HABIT — Generally a small tree 20-35 ft. or occasionally 50-75 ft. in 

 height with a trunk diameter of eight 'inches to 2% ft.; trunk erect or 

 inclined, frequently dividing into a number of ascending limbs with 

 slender scraggly branches forming a narrow oblong open head; often 

 spreading by underground stems and forming thickets of small trees. 

 A rapidly growing tree but short lived and subject to the attacks of 

 borers. 



BARK — Rough even on young trunks, dark reddish to yellowish- 

 brown, becoming deeply furrowed into rounded ridges, not flaky. 



TAVIGS — Rather slender, brittle, often zigzag, light reddish to green- 

 ish-brown, smooth or nearly so, more or less angled with decurrent 

 ridges from base and outer angles of leaf-scars, generally spiny with 

 paired stipular prickles at nodes. LENTICELS — pale, scattered. PITH 

 — wide, more or less angled. 



L.EAF-SCARS — Alternate, more than 2-ranked, generally large and 

 conspicuous, inversely triangvilar to pentagonal, raised, covering the 

 buds. STIPULES — in the form of prickles, sometimes poorly developed 

 or entirely lacking. BUNDLE-SCARS— 3. 



BUDS — Terminal bud absent; lateral buds minute, rusty-downy, 3-4 

 superposed, generally close together, enclosed in a rusty-downy cavity 

 below the leaf-scar, which cracks between the bundle-scars at the 

 development of a branch usually from the uppermost bud exposing the 

 long rusty hairs attached to under side of the three persistent lobes 

 of the leaf-scar; on rapidly grown shoots, the uppermost bud often 

 develops into a branch the first season, which may be rudimentary and 

 deciduous, leaving a small scar above leaf-scar. 



FRUIT — A dark brown flat pod, 5-10 cm. long, containing 4-8 small 

 brown mottled fiattish seeds, persistent on the tree throughout the 

 winter. 



COMPARISONS — The paired prickles at the nodes form the most 

 striking character of the Common Locust but since they are absent on 

 some twigs and entirely lacking on certain varieties, the hidden, closely- 

 packed downy buds must be taken as the chief distinguishing features. 

 They separate the Common Locust from the Honey Locust when the 

 characteristic branched thorns are not present on the latter species. The 

 Clammy Locust IRobinia viscosa Vent.] is a small southern tree fre- 

 quently cultivated and established at many points throughout New 

 England. It has the general characters of the Common Locust but 

 the stipular prickles are less well developed and its twigs are covered 

 with a sticky glandular coating. The Bristly Locust IRoMnia hispida 

 L.] is a mere shrub with twigs beset with bristly hairs but generally 

 without stipular prickles. The Prickly Ash or Toothache Tree 

 [Zanthoxylon americanum L.], a shrub occurring throughout New Eng- 

 land, resembles the Locust in its stipular prickles (lower twig in plate). 

 It is readily distinguished from the Locusts, however, by the red downy 

 exposed clustered buds, the presence of a terminal bud and the pun- 

 gent flavor of its twigs. 



DISTRIBUTION — In its native habitat growing upon mountain slopes, 

 along the borders of forests, in rich soils. Naturalized from Nova 

 Scotia to Ontario. Native from southern Pennsylvania along the 

 mountains to Georgia; west to Iowa and southward. Formerly much 

 planted as an ornamental and timber tree; more cultivated in Europe 

 than any other American tree. 



IN NEW ENGLAND — Maine — thoroughly at home, forming wooded 

 banks along streams; New Hampshire — abundant enough to be reel ->ned 

 among the valuable timber trees; Vermont — escaped from cultivation in 

 many places; Massachusetts, Connecticut and Rhode Island — common in 

 patches and thickets and along the roadsides and fences. 



W'OOD — Heavy, exceedingly hard and strong, close-grained, very 

 durable in contact with the soil, brown or rarely light green, witn 

 pale yellow sapwood of two or three layers of annual growth; exten- 

 sively used in shipbuilding for all sorts of posts, in construction and 

 turner.v; preferred for tree nails and valued as fuel. 



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