BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Krameria parvifolia | Range Ratany 



GENERAL BOTANICAL CHARACTERISTICS : 
Range ratany is a native, long-lived, deciduous, perennial shrub that
grows from 12 to 24 inches (30-60 cm) tall.  It is densely branched,
thorny, and drought resistant.  The leaves are alternate and pubesent;
flowers are irregular and purple in color; and the fruit is globose,
indehiscent, thick walled, and spiny [14,17,22,33].

The root system is shallow, with 40 percent of the root mass in the top
4 inches (10 cm) of the soil, and spreads horizontally and radially
[36].  The roots form grafts with members of the same or different
species forming protocooperation or a parasitic relationship.  These
relationships and the hypothesis that range ratany obtains atmospheric
moisture through its foliage may explain how it can maintain active
growth after soil moisture has dropped below 3 percent [35].


RAUNKIAER LIFE FORM : 
   Undisturbed State:  Phanerophyte (nanophanerophyte)
   Burned or Clipped State:  Cryptophyte (geophyte)


REGENERATION PROCESSES : 
Range ratany reproduces sexually by seed.  In years with high soil
moisture it will flower twice, in the spring and again in the fall
[31].


SITE CHARACTERISTICS : 
Range ratany's habitat is the desert environs, where it occupies open,
sandy to rocky flats, bajadas, and playas [17,31].

Soil:  Range ratany occurs in Alfisol, Aridisol, and Entisol soil orders
[12].

Climate:  Range ratany inhabits areas where the winters are short and
mild, and the summers are long and hot.  Precipitation is received
primarily in the fall and winter in the northern portion of its range
and in the summer in the southern portion.  The annual precipitation is
8 to 25 inches (20-65 cm) [8,9].

Elevation:  Range ratany generally grows at elevations ranging from 500
to 5,000 feet (150-1,500 m) [34].


SUCCESSIONAL STATUS : 
Range ratany is a component of some climax desert shrub communities
[37].  It is a dominant in the shrub live oak-mixed shrub and shrub live
oak-birchleaf mountain-mahogany (Cercocarpus betuloides) plant
associations [9].


SEASONAL DEVELOPMENT : 
Compared to associated species, range ratany remains dormant for at
least a month longer in the spring and retains its leaves for up to 2
months longer in the fall [1,35].

The mean dates and one standard deviation [(SD) in days] of the
phenological developement of range ratany are as follows [27]:

Development                     Date                    SD
---------------------------------------------------------------
Leaf budding                    April 7                 +/- 4.5
flowering                       May 5                   +/- 4.6
Fruiting                        May 22                  +/- 4.6

The phenological development of range ratany is based primarily on the
temperature regime and secondarily on the moisture regime [4,27].  It
does not go dormant during the summer no matter how dry the soil.  Range
ratany can photosynthesize when its water potential is at negative 72
bars.  Dormancy starts when night temperatures consistently drop below
40 degrees F (4 deg C) [1].

Related categories for Species: Krameria parvifolia | Range Ratany