BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Aesculus californica | California Buckeye 



GENERAL BOTANICAL CHARACTERISTICS : 
California buckeye is a large shrub or tree up to 23 feet (7 m) tall.
The 2-to 6-inch-long (5-15 cm) leaves are deciduous and palmately
compound [21].  Flowers are borne on a terminal panicle 4 to 8 inches
(10-20 cm) long.  The pear-shaped, light brown fruit contains one to six
glossy brown seeds 0.8 to 1.2 inches (2-3 cm) in diameter [5,21].


RAUNKIAER LIFE FORM : 
   Phanerophyte


REGENERATION PROCESSES : 
Sexual:  California buckeye reproduces by seed [5].  The average tree
produces approximately 100 seeds per year.  Seed dispersal is poor and
is accomplished mainly by gravity or water; dispersal by animals is rare
[13].  Seeds are viable for only 1 year and are shed from November to
mid-February [24].  Germination occurs within several weeks of shedding
if the soil temperature is above 40 degrees Fahrenheit (4 degrees C).
If the temperature persists below 40 degrees for 2 months or more the
seeds are susceptible to fungal infections or desiccation [12].
Germination success rates of 75 percent have been reported under
laboratory conditions [19].

Asexual:  California buckeye can sprout from the stump or root crown
[3,28].


SITE CHARACTERISTICS : 
California buckeye grows on dry slopes, in canyons, and along waterways
[5,21].  In the Central Valley it occurs along stream and river banks
[5,19].  It is associated with poison-oak (Toxicodendron diversilobum)
in most communities in which it occurs [5,17].
                
Soil:  California buckeye grows in sandy, sandy-loam, or gravelly-loam
soils [5].

Climate:  California buckeye occurs in a Mediterranean climate with cool
moist winters and hot dry summers [5,15,18].  The mean annual rainfall
is less than 14 inches, and temperatures are in excess of 100 degrees
Fahrenheit (38 degrees C) for several successive days every summer [14].

Elevation:  California buckeye occurs below 4,000 feet (1,219 m) [21].


SUCCESSIONAL STATUS : 
California buckeye exhibits both tolerant and intolerant
characteristics.  It occurs as a widely scattered individuals in open
grasslands.  It also occurs as an understory shrub in mixed evergreen
forest [3].  It is a climax indicator in chaparral and mixed oak
communities [1] and in California buckeye woodlands [8].
    


SEASONAL DEVELOPMENT : 
California buckeye flowers from April to September [24].  New leaves
emerge from March to June while soil moisture is abundant [20].  The
leaves dry up and are shed in late spring or early summer in Sierra
Nevada foothill populations but may be retained through fall in coastal
populations when soil moisture remains available [5].  Fruits ripen from
September to October and are dropped from November to December [24].

Related categories for Species: Aesculus californica | California Buckeye