J. D. Brackenridge, a botanist accompanying an expedition in the Mt. Shasta area of California, U.S.A., is credited with discovering Darlingtonia. After studying some specimens, J. Torrey concluded that there were sufficient differences between them and Sarracenia plants to warrant the formation of a new genus, which was named in honor of Torrey's friend and outstanding biologist Dr. W. Darlington. Later the name Darlingtonia californica was discovered to be invalid according to the international rules for naming plants and it was changed to Chrysamphora californica. This name was subsequently changed back to Darlingtonia californica because of widespread usage of the original name. Common names include Cobra Lily, California Pitcher Plant, and Cobra Plant.
The native habitat of Darlingtonia is the mountainous region from western Oregon southward to northern California, U.S.A., and in British Columbia, Canada. Plants grow in bogs or wet areas with high water tables such as borders of springs and streams.
Darlingtonia are herbaceous perennials. The leaves, which usually grow upright, form hollow pitchers that terminate in a dome from which 2 flaps of tissue, the fangs, project. The domed pitchers arise from a fibrous rooted rhizome. When the plants are mature the rhizome sends out stolons from which new plants develop. (Fig. 3-19) The pitchers have an unusual growth feature in that they twist just enough as they grow so that the opening of the pitcher is facing outward from the center of the plant. Each plant has from 5-15 leaves and usually 1 scape bearing a solitary flower.
The pitcher-shaped leaves may exceed lengths of 1 yd. (0.9 m) and terminate in a dome whose opening is to the front and below the dome. From the front edge of the opening hangs a fang-like appendage which presumably acts as a landing ramp for the prey. There are translucent areas on the dome called fenestrations which, to an insect inside the pitcher, may look like openings to the outside. (Photo 3-10) Juvenile leaves which are produced by seedlings, by side shoots from a rhizome and by cuttings lack the forked appendage and dome. Leaf color varies from green to yellowish-green mixed with red and maroon. In intense light the whole plant may be a solid maroon color.
The Darlingtonia flower consists of 5 long yellow-green sepals, 5 purple-pink petals, about 15 stamens and a 5-lobed compound pistil. It is pendulous on a tall scape which has numerous pink-lavender bracts that become papery and abscise as the ovary of the flower matures into a dry fruit containing seeds. (Fig. 3-20)
Coloration and the production of nectar are probably the most effective lures for attracting insects. The efficiency of the plants' trapping ability is attested to by its leaves or pitchers which are, more often than not, full of insects and their remains. Once the insect stumbles into the bottom area of the pitcher the downward pointing hairs that line the inside surface hinder the prey from climbing out. (Fig. 3-21)
Insects landing on the fangs are enticed toward the dome opening by the increased abundance of nectar just inside the mouth (opening) of the pitcher. Once inside the insect may try to fly out through one of the transparent areas in the dome, a fenestration, only to slam into it and drop down into the fluid below.
The interior of the Darlingtonia pitcher is similar to that of Sarracenia's pitchers. In some areas there are downward pointing hairs that direct the path of insects into regions that afford no foothold for them.
Until recently bacterial action was thought to be solely responsible for digestion in Darlingtonia, but it was discovered that at least one enzyme is secreted by the pitchers into the fluid bath. Here, as in the case of other Pitcher Plants, there are insects that are able to survive and thrive in the digestive bath living off the plants' captured prey.
SPECIES OF THE GENUS DARLINGTONIA
Darlingtonia is a monotypic genus; that is, there is only one species in the genus. CULTURAL INFORMATION Planting Media
Temperatures in its native habitat extend from below freezing to about 100°F (38°C). Even though the usual summer air temperature is about 80°F (27°C), the temperature of the soil is usually lower than 68°F (20°C). Greenhouse experience indicates that best growth occurs when soil temperatures range from about 60-68°F (16-20°C). During the winter the plants will have an adequate dormant period with temperatures ranging from 35-50°F (2-10°C).
To keep soil temperature at reasonable levels, grow plants out of direct sunlight and plant them in large pots. The more medium there is in the pot, the longer it will take for the soil temperature to increase during the day. Lower ambient night temperatures will allow the soil temperature to also drop at night and, therefore, be cool at the start of the next day. Copious watering during hot periods will help keep soil temperatures low. Some growers use ice water to keep the temperature under control. If plants are grown in an outdoor greenhouse, they should be placed on the floor where it is cooler than at bench level.
Darlingtonia require a rest period of 4-6 months at 35-50°F (2-10°C). Water & Humidity
During the growing season the growing medium can be quite wet, almost waterlogged, as long as the water is not stagnant. Keep the medium drier during the dormant period. The plants thrive best in a high humidity environment.
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