SO MISC. PUBLICATION 101, U. S. DEPT. OF AGRICULTURE 
PALOVERDES (CERCIDIUM SPP.) 
Cercidium *® is a semitropical or tropical American xerophytic 
genus of about 11 species, the Spanish-Mexican name referring to the 
smooth, bright (sometimes yellowish or brownish) green bark of 
most of the species. In periods of prolonged drought or other feed 
shortage paloverdes assume some local importance as emergency 
forage. ‘Their young branches and scanty foliage are ordinarily 
eaten but slightly by livestock in summer, but in the spring and after 
heavy rains or in the more moist situations at the eastern edge of 
their range the leaves become larger, more abundant, and more suc- 
culent, thus enhancing their forage value. The pods are nutritious 
and fairly palatable to livestock and are sometimes ground into meal 
for human consumption. For the traveler in the desert paloverdes 
provide both fuel, and fodder for his beasts of burden. The genus 
is also valued for erosion control in gulleys, as honey plants, and as 
food for birds. Three species are common in the Southwest. 
Border paloverde (C. floridum, syns. Parkinsonia florida, P. tor- 
reyana, C’. torreyanwm), known also as Texas paloverde (13/), 
ranges from southwestern Texas to southern California and south 
into Lower California and other parts of adjacent Mexico. 
Littleleaf paloverde (C. microphyllum, syn. P. microphylla), 
locally known as palo Christo, interesting comments on which are 
given by Kunzé (75) and Hornaday (64), is found in southern Cal- 
fornia, Lower California, southern Arizona, and Sonora. 
Texas paloverde, or dwarf paloverde (C. tewanwm, syn. P. tex- 
ana), a rigid bush 2 to 5 feet high, with only one or two pairs of 
leaflets, often forms dense thickets in the Rio Grande region of 
southwestern Texas. 
REDBUDS (CERCIS SPP.) 
Redbuds, sometimes called Judas-trees, are represented in the West 
by three species, but their leathery foliage ordinarily seems unaccefy °- 
able to livestock. California redbud (C. occidentalis) is cultivated 
as an ornamental. 
RATANY FAMILY (KRAMERIACEAE) 
RATANIES (KRAMERIA SPP.) 
Ratany is the only genus of its family and consists of about 20 
(North and South) American species, of which about five or perhaps 
six occur in the United States. The genus is of pharmaceutical in- 
terest as the source of rhatany root (Krameriae radix), which is a 
powerful astringent, useful in the treatment of chronic diarrhea 
19 Cercidium is regarded by many botanists as a synonym of Parkinsonia, but even those 
who recognize both genera usually place in Parkinsonia some species which would be 
better placed in Cercidium. As the nomenclature of these plants is so confused in litera- 
ture, it seems desirable to give a key to the two genera, based, to a large extent, on I. M. 
Johnston’s treatment (69) : 
Leaves eiongated; leaflets numerous (20 to 30 pairs, or even more), rather wide spaced ; 
rachis (main leaf axis, or petiole) very short, from the axil of a large spine, ending 
in a spiny tip; rachillae (axes of the pinnae, or two main leaf divisions) long, flat- 
tened, winged, and leaflike; sharp at the tip; flowers in an elongated raceme; calyx 
lobes strongly imbricated (i. e., edges overlapping) in bud. Pods terete (i. e., eylindri- 
cal, or nearly so), torose (conspicuously constricted between the seeds)__Parkinsonia. 
Leaves short; leaflets few, mostly 2 to 6 or occasionally 12 pairs, rather close together ; 
rachis (main leaf axis), or petiole, relatively long, not spiny or else with a short 
prickle at the base; rachillae (axes of the two main leaf divisions) short, rounded, 
neither winged nor leaflike; flowers in a short corymb; calyx lobes valvate or indu- 
plicate valvate (not overlapping) in bud. Pods either flattened or rounded (terete), 
either constricted between the seeds (torose) or not-------------_----- Cercidium, 
