LEGUMINOS&. SILVA OF NORTH AMERICA. 83 
CERCIDIUM FLORIDUM. 
Green Barked Acacia. 
LEGUME compressed, with straight acute margins. Leaflets green, slightly glandular. 
Cercidium floridum, Bentham; Gray, Smithsonian Con- Parkinsonia florida, Watson, Proc. Am. Acad. xi. 135. — 
trib. 1.58 (Pl. Wright. i.). — Walpers, Ann. iv. 594.— Brewer & Watson, Bot. Cal. i. 162.— Coulter, Contrib. 
Hemsley, Bot. Biol. Am. Cent. i. 327. — Sargent, Garden U. S. Nat. Herb. ii. 94 (Man. Pl. W. Texas). 
and Forest, ii. 388. 
A tree, eighteen to twenty feet in height, with a short crooked trunk eight or ten inches in 
diameter and stout spreading branches covered with thin smooth bright green bark, and forming a 
low wide head. The bark of the trunk is a sixteenth of an inch thick, light brown tinged with green, 
with numerous short horizontal light gray ridge-like excrescences on its otherwise smooth surface. 
The branches are light or dark olive-green, slightly puberulous at first but soon glabrous; they are 
marked by a few black lenticular dots and are armed with slender spines an inch or less in length. 
The leaves appear in Texas in April, and farther south probably a month earlier, and remain on the 
branches until October; they are an inch or an inch and a half long, with two or rarely three pinne, 
broad pubescent petioles and rachises, and oval or somewhat obovate dark green puberulous and mi- 
nutely glandular leaflets about a sixteenth of an inch in length, which are borne on short stout pubes- 
cent petiolules, rounded or slightly emarginate at the apex, and when they unfold are covered on the 
lower surface with scattered white hairs. The flowers, which are three quarters of an inch across 
when expanded, open in April with the leaves, and are produced in successive crops during three or 
four months, flowers and fully grown fruit appearing sometimes together on the same tree; they are 
borne in four or five-flowered racemes, with slender stems and branches furnished with small acu- 
minate membranaceous caducous bracts. The flower-buds are oval or obovate, rounded at the apex, 
of a tawny orange color, and, like the young pedicels, faintly pilose. The legumes are compressed, 
oblong, straight, or slightly falcate, acute, with a narrow and acutely margined ventral suture; they 
are tardily dehiscent, with papery valves which are yellow tinged with brown on the outer surface and 
bright orange-colored within. They are from two to two and a half inches long, half an inch broad, 
two or three-seeded, and, like the ovary, quite glabrous. The seeds are a third of an inch long and 
compressed, with thin albumen covering the sides only of the bright green embryos. 
Cercidium floridum is distributed from the shores of Matagorda Bay to Hidalgo County in 
western Texas! and to northern Mexico, where it abounds on dry gravelly mesas from the mouth of 
the Rio Grande to the foothills of the Sierra Madre, and in many of the low valleys in the neighbor- 
hood of Monterey. It is not common in Texas, where it appears to have been first noticed in 1881 
by Mr. 8. B. Buckley, but in Mexico it forms a conspicuous feature in the region which it inhabits, 
enlivening it with its bright green branches, and in spring and early summer with its abundant brilliant 
golden flowers. 
The wood of Cercidium floridum is light, soft, and close-grained, with a smooth satiny surface, 
and contains numerous thin prominent medullary rays, and bands of from one to three rows of open 
cells which mark the layers of annual growth. It is pale yellow tinged with green, the thick sapwood 
1 Where it was collected by G. C. Nealley in 1889. (See Coulter, Contrib. U. S. Nat. Herb. ii. 94 (Man. Pl. W. Texas], under 
Parkinsonia Torreyana.) 
