BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Eriodictyon californicum | Yerba Santa 



GENERAL BOTANICAL CHARACTERISTICS : 
Yerba santa is an erect, much-branched, native evergreen shrub from 2 to
8 feet (0.6-2.4 m) in height.  The branches are glutinous or resinous;
lanceolate leaves are glutinous on top.  Mature leaves are often
blackened by a sooty fungus [25,27].  The root system is shallow, with
multibranching rhizomes.  Most of the main roots are confined to the top
3 inches (7.6 cm) of soil [9,20].  The fruit is a small capsule, 0.08 to
0.12 inch (2-3 mm) long, containing two to eight small seeds [25].


RAUNKIAER LIFE FORM : 
   Phanerophyte


REGENERATION PROCESSES : 
Sexual:  Yerba santa reproduces from seed [25,27,28].  Seedlings may be
adundant after fire [37].  They emerge 1 to 3 weeks later than seedlings
of other brush species, and experience high mortality [28].  Yerba santa
seedlings are poor competitors.  Seedlings are particularly sensitive to
emerging herbaceous species [6,19,28].  A seedbed rich in herbaceous
species will competitively eliminate most emerging yerba santa seedlings
[19].  Surviving seedlings grow rapidly.  Schultz and Biswell [28]
reported seedlings attaining heights of up to 20 inches within the first
season.  Plants become sexually mature within 2 or 3 years.  Most seed
falls beneath the parent plant.  The seed is very small, and is readily
buried beneath the litter layer, duff, and soil to become part of the
seedbank.  Seed germinates following a disturbance such as fire or
mechanical site preparation [6].  Longevity of soil-stored seed is
unknown [37].

Vegetative:  Yerba santa regenerates asexually through rhizomes, which
may be produced as early as the first growing season following seedling
establishment [6,11,19,33].  Vegetative reproduction is the most
successful method of self-propagation in established communities [6].
Biswell [37] reported that rhizomes may grow as much as 8 feet (2.5 m)
in one summer, giving rise to plants every 8 to 10 inches (20-25 cm).
Vegetatvie growth is not usually this rapid, such rapid grow may occur
on ash beds after fire if soil is fertile and moisture adundant.


SITE CHARACTERISTICS : 
Yerba santa occurs on dry, rocky slopes and ridges.  It is common on
south- or east-facing slopes [25,33].

Elevation:  Yerba santa occurs below 5,500 feet (1,676 m), with a
mean elevation of 2,120 feet (636 m) [1,25].  

Soil:  Yerba santa grows in shallow to deep, slightly acidic soil. 
Soil texture varies from sandy loam to heavy clay [5,6,8,28]. 
It will tolerate serpentine soil [15,21].

Climate:  Yerba santa occurs in a Mediterranean climate with wet, mild
winters and hot, dry summers.  Snow showers occur during the winter
months but usually melt off rapidly [23].  Soil temperatures are
frequently below freezing in winter [29].

Associated species:  Associated species include chaparral whitethorn
(Ceanothus leucodermis), wedgeleaf ceanothus (C. cuneatus), manzanita
(Arctostaphylos spp.), tree poppy (Dendromecon rigida), broadleaf and
redstem filaree (Erodium botrys and E. cicutarium), soft chess (Bromus
mollis), and foxtail fescue (Festuca megalura) [28,29,36].  (also see
SAF cover types)


SUCCESSIONAL STATUS : 
Yerba santa is both a residual colonizer and a survivor in disturbed
communities, establishing either from seed or by sprouting from rhizomes
[6,24,29].  Mature shrubs are found in early seral communities.  It is a
diminished survivor, however.  It is shade-intolerant, and plants
gradually die out as the community matures.  Yerba santa is displaced in
climax communities by chaparral whitethorn, wedgeleaf ceanothus, and
various manzanitas [21].


SEASONAL DEVELOPMENT : 
The seasonal development of yerba santa is as follows [20,25,28]:

     vegetative growth begins - April
     flowers in bloom - May to June
     seed ripe - September
     seed dissemination - September to November
     germination - March
     seedlings emerge - April

Related categories for Species: Eriodictyon californicum | Yerba Santa