110 
SILVA OF NORTH AMERICA. 
NYCTAGINACES. 
long semiprostrate vine-like stems, and an inhabitant of nearly all tropical countries, and of southern 
Florida, where two other species occur; of these one is a small tree, and the other, Pisonia rotundata,' 
is a low shrub. 
The roots of Pisonia possess purgative and emetic properties, and are sometimes employed in 
medicine.” From the leaves of Pisonia tomentosa,’ the Pao Lepra of Brazil, a black dye is obtained.* 
In India impenetrable hedges are made with the long semiscandent stems covered with stout hooked 
prickles of Pisonia aculeata, which is often planted for this purpose.® 
The generic name, first proposed by Plumier® and adopted by Linnzus, commemorates that of 
Willem Piso,’ the Dutch physician and naturalist who first studied the natural products of Brazil. 
iii. 146, t. 121. — Chapman, Fl. 374.— Grisebach, Fl. Brit. W. Ind. 
70.— Bentham, Fil. Austral. v. 279. — J. A. Schmidt, Martius Fi. 
Brasil. xiv. pt. ii. 351, 354. — Hemsley, Bot. Challenger Exped. i. 
pt. iii. 181. — Hooker f. Fl. Brit. Ind. iv. 711. 
Pisonia villosa, Poiret, Lam. Dict. v. 347 (1804). — Choisy, 
De Candolle Prodr. xiii. pt. ii. 440. 
Pallavia aculeata, Vellozo, Fl. Flum. 121; Icon. iv. t. 12 
(1825). 
Pisonia loranthoides, Humboldt, Bonpland & Kunth, Nov. Gen. 
et Spec. Suppl. vii. 197 (1825). 
1 Grisebach, Cat. Pl. Cub. 283 (1866).— Chapman, FV. ed. 2, 
Suppl. 644. 
2 Rosenthal, Syn. Pl. Diaphor. 227, 1111. — Eichler, Martius Fi. 
Brasil. xiv. pt. i. 375. 
8 Casaretto, Nov. Stirp. Bras. Dec. viii. 69 (1844). — Choisy, 1. e. 
445. — J. A. Schmidt, J. c. 363, t. 84. 
Pisonia noxia, Netto, Ann. Sci. Nat. sér. 5, v. 80, t. 7 (1866). 
The popular name of this tree, which is also called Pao Judeu, 
is due to the belief among the inhabitants of Minas Geraes that 
leprosy is brought on by sleeping under the shade of its leaves, 
which are furnished on the under surface with short deciduous 
irritating hairs (Netto, J. c. 81). 
* Netto, J. c. 82. 
5 Balfour, Encyclopedia of India, ed. 3, iii. 226 (under Pisonia 
villosa). 
6 Nov. Pl. Am. Gen. 7, t. 11. 
7 Willem Piso, 2 Dutch physician and naturalist, practiced 
medicine in Leyden and Amsterdam, and in 1637 visited Brazil, 
accompanied by Georg Marggraf, under the auspices of the Duke 
of Nassau. In 1648, four years after the death of Marggraf, Jan 
de Laet published in Leyden and Amsterdam the classical His- 
torie Rerum Naturalium Brasilie Libri VIII., containing a record of 
the observations of the two naturalists, to which was added a work 
by Piso upon the Brazilian materia medica. After the death of 
the Duke of Nassau in 1679, Piso entered the service of the 
elector Frederick William. 
