BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Darlingtonia californica | California Pitcher Plant 



GENERAL BOTANICAL CHARACTERISTICS : 
California pitcher plant is a native perennial forb.  It is a
carnivorous plant that traps insects in its unique leaves.  With
plentiful light and water in its open bog habitat, the production of
nectar is relatively "cheap".  Insects attracted by the nectar are used
as a nutrient source [15].  Adult California pitcher plants have slowly
spreading rhizomes which produce a single leaf (pitcher) and roots at
each node [11,26].  The diameter of the rhizome is from 0.6 to 0.8 inch
(15-20 mm), although it narrows near the apical tip [11].  Internodes
are short and the pitchers appear to arise in a terminal rosette [33].
Each leaf has a sheathing base that encloses the apical bud and the base
of the next leaf [11].  Individuals have been aged by counting old leaf
bases attached to the rhizome [18].  Pitcher size may vary from over 39
inches (1 m) to as small as 0.4 inches (1 cm), although most pitchers
are between 8 and 24 inches (2-6 dm) tall [14,27,28].

Pitcher Morphology:  Germinating seeds of California pitcher plant have
3 lanceolate and nontubular cotyledons which are followed by 5 to 10
juvenile leaves from a basal rosette [11,12].  Juvenile leaves are
tubular and somewhat twisted so that the opening may either be erect or
horizontal.  Above the opening, each of these leaves tapers into a
flattened beak and the outside surface has many nectar glands [12,23].
The distinctive adult leaves have an elongated tubular portion with a
keeled area the length of the tube.  The tube is twisted from 90 to 180
degrees.  Functionally, the twisting turns the mouth of the tube to one
side making it more accessible to insects and preventing the next leaf
from growing into the mouth and plugging it [11].  At the top of the
tube, a hood arches over the mouth.  The front edge of the hood has a
curious appendage shaped like a fishtail hanging in front of the mouth.
The outer surface of the fishtail appendage has many nectaries, with
nectar concentrated along the rim of the fishtail and opening of the
pitcher [32,33].  At maturity, groups of hood cells lose chlorophyll and
become translucent windows or fenestrations.  The inner walls of the
hood have short, stiff, downward or backward pointing hairs.  Below the
nectar roll at the mouth's edge, the inner walls are smooth and waxy
with long, thin hairs pointing downward near the base [32,33].  Pitchers
contain water secreted by the leaf, while rainwater is excluded by the
hood [23,18,28,33].  This fluid increases in volume as insects or other
nitrogen containing materials are added to it [23,18,33].

Pitcher Ecology:  Insects are attracted to pitchers by the color and
nectar glands which cover the outside of the hood but which are more
numerous on the fishtail and wing [26].  There is a heavy exudation of
nectar on the nectar roll inside the mouth of the pitcher.  Light from
the hood fenestrations assists in attracting insects inside the hood
[25].  The fenestrations also may appear to be exits and confuse some
insects [26].  Insects rarely escape once they have fallen into the
fluid at the pitcher base [26].  However, many if not most insect
visitors ingest nectar and leave without becoming trapped [15].  This
system may be mutually beneficial to both the California pitcher plants,
which gain a nutrient source, and the insect visitors, which gain a
nectar source [15].  The bodies of insects which drown in the pitchers
decompose by bacterial action, as California pitcher plant secretes no
enzymes for that purpose [23,33].  Twenty or more arthropod species may
be found living in pitchers of California pitcher plants, many of which
are obligate inhabitants [8,29].  Larvae of several species feed on dead
insects trapped by the pitchers, thus increasing the rate of
decomposition [28].  Spiders construct webs in the domes [8].  Some
insects feed on pitcher tissue or lay eggs in the pitchers so that their
larvae can feed on them [8].



RAUNKIAER LIFE FORM : 
   Geophyte


REGENERATION PROCESSES : 
Vegetative reproduction of California pitcher plant by rhizomes is more
common than sexual reproduction [32].  Each leaf axil contains a single
bud which can develop into a lateral rhizome branch [11].  Although most
remain dormant, the buds that grow can cover a suitable location with
California pitcher plants [11,32].

Each pendant flower is borne on a stalk up to 39 inches (1 m) tall
[14,27].  The yellowish sepals are longer than the closed, reddish
corolla, which has openings to admit insect pollinators at indentations
near the ends of the petals [32,33].  The corolla shape, bell-shaped
ovary, and positions of both stigma and stamens greatly increase the
probability of cross-pollination [32].  Each five-chambered capsule
bears a hundred or more seeds which are 0.08 to 0.1 inch (2-3 mm) long,
hairy, and light reddish-brown [14,26,27].  The more rounded end of each
seed has many short projections which may aid in animal dispersal and
help the seed float [32,43].  Seeds mature within 10 weeks of
fertilization [33].


SITE CHARACTERISTICS : 
Along the Oregon and northern California coast, California pitcher plant
is found in sphagnum bogs, seeps, and along trickling streams [14,30].
In the Siskiyou Mountains it is found only on sites with running water
[1].  In California's Klamath Ranges and the northern Sierra Nevada,
California pitcher plant grows where there are slowly draining bogs
formed by springs or seepage slopes and open marshy meadows [34].  It is
very rarely found in bogs with standing water.  Normally it is
restricted to sites where its rhizomes and roots can be kept cool by
cold, moving water [26,32,33].  

In northwestern California, bogs with California pitcher plant as the
dominant vascular species intermingle with bog forests where
Port-Orford-cedar (Chamaecyparis lawsoniana), western white pine (Pinus
monticola), and shore pine (Pinus contorta) dominate [17].  Other plants
found with California pitcher plant include sundew (Drosera
rotundifolia), northern grass-of-parnassus (Parnassia palustris), common
butterwort (Pinguicula vulgaris), California coneflower (Rudbeckia
californica), smallhead burnet (Sanguisorba microcephala), lance-leaved
violet (Viola lanceolata occidentalis), white rushlily (Hastingsia
alba), California bog-asphodel (Narthecium californicum), western
tofieldia (Tofieldia glutinosa occidentalis), California ladyslipper
(Cypripedium californicum), canyon bogorchid (Habenaria sparsiflora),
hairy bulrush (Scirpus criniger), lilies (Lilium spp), rushes (Juncus
spp.), and beaked-rushes (Rhynchospora spp.) [34].  In lower elevation
bogs near the ocean, some associated species include Yosemite aster
(Aster occidentalis var. yosemitanus), scarlet paintbrush (Castilleja
miniata ssp. elata), Mendocino gentian (Gentiana setigera), California
coneflower, Pacific reedgrass (Calamagrostis nutkaensis), smallhead
burnet, largehorned butterwort (Pinguicula macroceras), and tufted
hairgrass (Deschampsia caespitosa ssp. beringensis) [17].

Soils:  California pitcher plant commonly grows on sphagnum or poor peat
soils and gravel where the parent material is serpentine.  It is often
considered an indicator of serpentine [14,26,32,38,39].  It is also
found on olivine grabbro in the central Siskiyou Mountains [39].

California pitcher plant occurs from sea level to 8,500 feet (2,592 m)
in elevation [27,33].


SUCCESSIONAL STATUS : 
Obligate Initial Community Species

Bogs containing California pitcher plant can develop directly from wet
sand on deflation plains along the Oregon coast [41].  Carnivorous
plants are characteristic of an early stage of succession in bog
habitats.  Their growth helps build soil which can then be occupied by
other perennials, shrubs, and eventually trees [39].  Pitcher plants in
the southeastern United States do not compete well with other plants in
the absence of fire or other disturbance [15].  California pitcher plant
is primarily found in the bright sunshine of open bogs [10,21].



SEASONAL DEVELOPMENT : 
Flowers are initiated during late summer, overwinter as buds and bloom
in early spring before new leaves appear [43].  Bloom can be from April
to August depending on altitude [28,32].  The first pitchers produced
after bloom are the tallest of the year [28].  Annual growth of the
rhizome may include one or two full-sized pitchers, one that is half
size or smaller, and three to five very small pitchers [29].  The
smallest pitchers tend to be prostrate, with the fishtail appendage
touching the ground and forming a ramp for insects [23].

Related categories for Species: Darlingtonia californica | California Pitcher Plant