RHAMNACEA. SILVA OF NORTH AMERICA. 29 
RHAMNIDIUM FERREUM. 
Black Iron Wood. 
CALYX-LOBES conspicuously crested; petals 0. Fruit fleshy, the stone thick and 
bony. 
Rhamnidium ferreum, Sargent, Garden and Forest, iv.16. Condalia ferrea, Grisebach, F7. Brit. W. Ind. 100. — Wal- 
Rhamuus ferrea, Vahl, Symb. iii. 41, t. 58. pers, Ann. vii. 588. — Gray, Bot. Gazette, iv. 208. — 
Zizyphus emarginatus, Swartz, Fl. Ind. Oce. iii. 1954. Chapman, F7. Suppl. 612. — Eggers, Bull. U. S. Nat. 
Myginda integrifolia, Lamarck, Dict. iv. 396. Mus. No. 13, 40.— Sargent, Forest Trees N. Am. 10th 
Ceanothus ferreus, De Candolle, Prodr. ii. 30. Census U. S. ix. 39. — Trelease, Trans. St. Louis Acad. 
Scutia ferrea, Brongniart, Mém. Rhamnées, 56; Ann. Ses. v. 362. 
Nat. x. 363 (not Chapman, FZ. 72). 
A low tree, rising sometimes to a height of thirty feet, with a slender trunk eight or ten inches in 
diameter, but generally much smaller and more often shrubby than arborescent in habit. The bark of 
the trunk is a quarter of an inch thick, and divided into prominent rounded longitudinal ridges, their 
surface broken into short thick light gray scales. The bark of the branchlets when they first appear is 
green and covered with dense velvety pubescence ; it is glabrous in the second year, and is then gray 
faintly tinged with red and roughened with small crowded lenticels. The leaves are conspicuously 
netted-veined, glabrous with the exception of a few scattered hairs on the upper surface and _ petioles, 
broadly elliptical, emarginate-mucronate at the apex, an inch or an inch and a half long, and three quar- 
ters of an inch to an inch broad, with entire or wavy margins. They are borne on stout petioles a 
quarter of an inch long, are rather thin but coriaceous, bright green and lustrous on the upper surface, 
and pale yellow-green below, and remain on the branchlets two or sometimes three years; the stipules 
are acuminate, membranaceous, and early deciduous. The flowers are produced on the shoots of the 
year in three to five-flowered cymes borne on stout peduncles sometimes half an inch long, or usually 
much shorter and often branched near the apex. The pedicels are slender, bibracteolate, a quarter of 
an inch long and twice the length of the yellow-green calyx, which is conspicuously crested on the inner 
surface of the acuminate lobes. The fruit, which is usually solitary, is borne on stems a third of an 
inch to half an inch long; it is globose-ovoid and a third of an inch long, with thin black flesh. 
Rhamnidium ferreum is widely distributed in southern Florida from Cape Canaveral on the west 
coast through the southern keys to the shores of Bay Biscayne. It inhabits Ste. Croix,’ San Domingo,’ 
St. Thomas,? Porto Rico,* Jamaica, and probably the other West India islands. On the Florida keys 
Rhamnidium ferreum is one of the most common of the small trees which, with the Eugenias, the 
Reynosia, the Citharexylum, and the Pisonias, compose a large part of the shrubby thickets which have 
replaced their original forest covering. 
The wood of Rhamnidium ferreum is exceedingly heavy, hard, strong, and close-grained, although 
brittle and difficult to work. It contains numerous thin medullary rays, and is rich orange-brown in 
color, the thin sapwood being lighter colored. The specific gravity of the absolutely dry wood is 
1.3020, a cubic foot weighing 81.14 pounds. The wood of this tree is remarkable for the large amount 
of ash — 8.31 per cent. — which is left when it is burned. 
Rhamnidium ferreum was discovered in Florida on Key West in 1846 by Dr. Ferdinand Rugel. 
1 Vahl, l. ¢. 8 Eggers, No. 171. 
2 Eggers, Fl. Ind. Occ. Exs. 1887, No. 1925. * P. Sintenis, Plante Portoricenses, No. 4824. 
