SALICINEE. 181 
2. Populus canadensis, Desf. Cat. Hort. Par. 
y. angustifolia, Wesm. in DC. Prodr. xvi. 2, p. 329; James in Long’s Exped. i, 
p. 497 (species) ; Torr. in Ann. Lyc. N. York, ii. p. 249; Nutt. Sylva, i. t. 16; Torr. 
Bot. U.S. & Mex. Bound. Surv. p. 204. 
OREGON southward.—NortH Mexico, on the Mimbres,. within the old boundary 
(Bigelow). Hb. Kew. 
The other varieties of this species have a wide range in North America, 
3. Populus mexicana, Wesm. in DC. Prodr. xvi. 2, p. 328. 
SoutH Mexico, road from Puebla to Real del Monte (Berlandier). 
Parry and Palmer collected specimens of two species of Populus in the region of 
San Luis Potosi, one of which may be this species. 
| Order CXXXIII. LACISTEMACEZ. 
Lacistemacee, Benth. et Hook. Gen. Plant. iii. p. 412. 
A monotypical Order of shrubs and small trees inhabiting Tropical America. 
1. LACISTEMA. 
Lacistema, Sw. Prodr. p. 12, et Fl. Ind. Occ. ii. p. 1091, t. 21; Benth. et Hook. Gen, Plant. iii. 
p. 413, | 
Sixteen species are enumerated, ranging from Mexico and the West Indies to Peru 
and Brazil, and most numerous in the last country. 
1. Lacistema myricoides, Sw. Prodr. p. 12, et Fl. Ind. Occ. ii. p. 1093, t. 21; 
DC. Prodr. xvi. 2, p. 591; Schnizl. in Mart. Fl. Bras. iv. 1, p. 282, t. 81. fig. 3. 
South Mexico, Mirador and Tlapacoyo (Liebmann); GuatemaLa (Friedrichsthal) : 
Nicaragua (Tate, 353); Panama, Chagres (Fendler, 282).—CoLomBia to Perv and Brazib 
and in the West Inpizes. Hb. Kew. 
[The Emperraces are a small Order of four dwarf shrubby species, referred to three 
genera. With the exception of one species in South-western Europe and the Azores, 
they are North-American; and one of them (Empetrum nigrum, L.) has a wide range 
in the arctic and alpine regions of the northern hemisphere, reappearing in the Andes 
of South America, and extending to Tierra del Fuego and Tristan d’Acunha. | 
Order CXXXIV. CERATOPHYLLEZ. 
Ceratophyllee, Benth. et Hook. Gen. Plant. iii. p, 415. 
A monotypic Order of aquatic herbs. 
