0 
may be mentioned as those containing our chief information: 
The Species plantariim of Linnaeus (1753) of course forms the 
groundwork; Walter, Flora Caroliniana (1788); Michaux, Flora 
Boreali- Americana (1803); Persoon, Synopsis plantaimm (1805); 
Pursh, Flora Septentrionalis (1814); Rafinesque, in various 
scattered publications (1815-40); Nuttall, Genera (1818), besides 
much material published in Torrey and Gray’s FI. N. Am.\ 
DeCandolle, Vol. IV (1830); Hooker (W. J.), 
B or calu Americana (1833-40). 
The list of publications containing descriptions of new species 
since Torrey and Gray’s Flora JV. Am. Vol. I (1838-40) is as 
follows : 
% 
Hooker and Arnott; Botany Beectiey Voyage (1841). 
Hooker: London Jour. Bot. vi. (1843), 
Buckley; Am. Jour. Sei. I. xlv. L843); Proc. Philad. Acad. (1861). 
Gray: PL Fendlerianae (1848); PL Wrightianm (1850); PL Lindheimer- 
ianee (1850); Manual (1856-67): Proc. Amer. Acad, vi., vii. (1868), viil. 
(1870); Pacif- E. E. Eept. xii. (1860); Ives’ Eeport (1861); Am. Jour. Sci, 
II. xxxlii. (1862); Proc. Philad. Acad. (1863). 
Torrey and Gray: Pacif. E. E. Kept. ii. (1854). 
Torrey: Mex. Boundary Survey (1858). 
Chapman: Manual Southern States (1860). 
Wood: Class-Book (1860). 
Watson: Bot. King’s Exped. (1871); Am. Naturalist, vii. (1873); Botan^^ 
of California (1876 and 1880); Proc. Amer. Acad. xi. (1876), xii. (1877), xiv. 
(1879), xvii. (1882), xviii. (1883), xx. (1885), xxi. (1886), xxii. (1887). 
Parry: Americair Naturalist, ix. (1875). 
Kellogg: Proc. Calif. Acad. i. (1876). 
Curran: Bull. Calif. Acad. iii. 
Coulter & Eose: Bot. Gazette, xii. (1887), xiii. (1888). 
Morong: Bull. Torrey Bot. Club, xiv. (1887). 
Geographical distribution. — The order contains about 160 
genera and 1300 species, mostly distributed throughout temperate 
regions and extending into the tropics along mountain systems. 
Its most abundant representation is in northern Europe and Asia. 
The genera are usually widely distributed, while most of the 
species are quite restricted. North America, north of Mexico, 
contains 59 genera and 233 species; of these, 7 are introduced 
genera, leaving us 52 native genera, only 22 of which are strictly 
North American; while of our species 217 are indigenous, and but 
13 of these are found at all in other countries. Of our native 
