124 BOTANICAL GAZETTE (AUGUST 
temperate habitat in both North and South America. The more 
pronounced xerophytic genera occupy the Lower Sonoran zone 
in North America, and similar portions of southern Brazil, Uru- 
guay, Argentine, and in a few cases Chili, being connected © 
through the gulf region rather than along the Andes, Certain 
of the genera, as Pfaffia, Iresine, and perhaps Alternanthera, are 
more nearly tropical, and prevail in the territory encircling the 
gulf of Mexico. Three genera, Cladothrix, Gossypianthus, and 
Dicraurus, are confined to the Lower Sonoran zone. Guillemi- 
nea extends from this zone along the Andes to Peru, G. densa 
having the distribution of the genus. Frcelichia has several dis- 
tinct species in the two extra-tropical zones, with one, 7. lori- 
dana, generally distributed and perhaps in both. 
Gomphrena affords the most noteworthy case of distribution. 
Of the ninety species, more than sixty are of extra-tropical 
South America, more than ten are Sonoran, and fifteen natives 
of Australia. G. globosa is the cosmopolitan member. It appears 
that the Australian species are quite as closely related to the 
South American as are those of the Lower Sonoran zone, and 
all three regions would indicate a distribution analogous to that 
I have shown in the case of the Frankenia § Toichogonia- 
Cosmopolita.s 
In so far as special contrivances for distribution are present 
they are as follows: 
1. The stems are jointed and fragile, and the flowers easily 
disarticulate from the rachis. . 
2. The perianth is beset with long woolly hair in most of the 
genera. 
3- The perianth is furnished with stout barbed hairs 
( Alternanthera repens) or with setose or spiny excresences 
(Freelichia). 
4. The bracts are long and spiny tipped (Gomphrena, Alter- 
nanthera). 
These characters would aid the fruit in adhering to hairy oF 
woolly mammals. 
5Geog.-Distr. of Frank. Engler’s Botan. Jahrbiicher 24 : 407. 
