floras are Concerned: Michaux (1803)! does not extend the geo- 
graphic range of Opuntia south of the Carolinas, Pursh (1814)? 
similarly limits the range southward, Nuttall (1818)? extends the 
range to Florida, and Darby (1841)* records a single species as 
being common in the southern states, while Chapman (1860, 
1883, 1897),5 records four species for the state. The latest 
American monograph! of the genus Opuntia cites only two species 
as growing in Florida. 
The writer became interested in the prickly-pears of Florida 
in 1901, when an upright plant with copiously tuberous roots 
was discovered at Miami. This plant was later described as 
Opuntia austrina and represents the widespread inland species 
of peninsular Florida. For a decade my work was confined 
mainly to tropical Florida, and aside from the species just men- 
tioned, only the common and widely distributed coastal forms 
were encountered. However, a few years ago when opportunities 
to travel more extensively in the state presented themselves, 
various heretofore unobserved kinds of prickly-pears came to 
light. Many parts of the state have now been visited; but little 
known, as well as almost wholly uninhabited extensive areas, 
both in the interior and in the eastern and western coastal regions 
and the unknown country back of Cape Sable still remain to be 
explored. 
In addition to field observations, we have had the advantages 
offered by the extensive cactus plantation of Mr. Charles Deering 
at Buena Vista, Florida, in which the writer has had all possible 
facilities extended to him and where he has introduced to cultiva- 
tion the species and forms of cacti he has met with in Florida and 
the other southeastern states. In this plantation, where the 
prickly-pears have nearly or quite natural conditions and a 
continuous growing season for twelve months each year, it has 
been possible to study and compare the vegetative and floral 
1 Flora Boreali-Americana 282. 
Flora Americae Septentrionalis 327. 
+ Genera of North American Plants 1: 206. 
* Botany of the Southern States, 322. 
5 Flora of the Southern United States, ed. 1 and 2, 144, ed. 3, 171. 
§ Contributions from the National Herbarium 3: 355-462. 
