Cobra Lily (California Pitcher Plant)

Phân loại học

Gia đình:	Sarraceniaceae
Chi:	Darlingtonia
Đặt hàng:	Ericales

Tổng quan

Darlingtonia californica, the cobra lily, is a pitcher plant of northern California and southwestern Oregon whose hooded pitchers resemble a rearing cobra with a forked tongue. It grows where cold water flows through the soil, and keeping its roots cool is the key to growing it.

Darlingtonia californica is the only species in its genus and belongs to the American pitcher plant family, Sarraceniaceae, with Sarracenia and Heliamphora. Its leaves are tubular pitchers that end in a swollen hood. A forked appendage, described as fangs or a moustache and ranging from yellow to purplish green, hangs below the small entrance under the hood. The hood is set with many translucent, glassy patches.

Pitchers are green in moderate light and become flushed with red in strong sun. The first pitchers of each season are much larger than those produced later in summer. Plants spread by underground stolons, sometimes a meter long, that produce new plants at their tips; no other member of the family is known to do this. The root system is large and rambling compared with that of other Sarraceniaceae.

In spring mature plants produce a single nodding flower on a stalk slightly taller than the pitchers, with five long green sepals and red-veined petals. Two forms are recognized: the usual form and f. viridiflora, an anthocyanin-free plant with no red pigment in leaves or flowers, known from one site in the Sierra Nevada of California.

Thông tin địa lý

Khu vực bản địa: Northern California and southwestern Oregon, north along the Oregon coast to Tillamook County, USA

Vùng khí hậu: Mediterranean (Köppen Csb); cool coastal to near-alpine sites

The cobra lily is restricted to places with year-round water flow: fens, seeps, sphagnum bogs, stream and pond margins and dripping cliff faces, from the seacoast to near-alpine elevations. The typical site is a slope with cold spring water running through the soil at or just below the surface. It most often grows on nutrient-poor serpentine (ultramafic) rock, which is toxic to most competing plants, and also on nutrient-poor sands and gravels. The climate is Mediterranean, with cool to cold, wet or snowy winters and mild, dry summers. The plants enjoy full sun but are often found in partial or even dense shade. Periodic wildfire keeps the habitat open, and the plant can regrow from its roots after fire.

Đặc điểm vật lý

Kích thước trưởng thành: Clumping; spreads by stolons up to about 3 ft (1 m) long

Tốc độ tăng trưởng: Slow

Loại bẫy: Pitfall Trap

The trap works like a pitfall with elements of a lobster pot. Colorful leaves give off a honey-like scent, and nectar is secreted in abundance on the forked 'fangs'. Insects feeding there crawl up toward the entrance hidden beneath the hood. Inside, the many translucent patches act as false exits: insects fly at them repeatedly until they tire and fall. The tube below is slick and lined with downward-pointing hairs, leading to fluid at the base.

Unlike Sarracenia, the pitcher does not collect rain; the plant pumps water into it from its roots. Digestion relies heavily on bacteria and other organisms living in the fluid, such as larvae of the midge Metriocnemus edwardsi, although studies have found that the plant secretes at least one protein-digesting enzyme of its own.

Hướng dẫn chăm sóc

Yêu cầu về ánh sáng

Strong light; full sun if it does not overheat the plant. Indoors or for seedlings, give as much LED light as possible without making the plants hot. Plants in humid, warm places can take sun; where humidity is low or variable, part shade suits them better.

Full sun in season hằng ngày

Nhu cầu về nước

Kiểu: Pure water (distilled or reverse osmosis), as cool as possible

Phương pháp: Water from above, regularly, ideally in the early morning when water is coolest; many growers water every day. Tall pots may stand in a few centimeters of water, but avoid stagnant, stinky soil, which leads to root rot. In hot weather growers place ice cubes of pure water on the soil, pump cooled water through the pots, or keep pots in the ground or in shaded, deep trays to hold the roots cool.

Tính thường xuyên: Daily top watering in the growing season

Độ ẩm: Not critical if roots are cool; moderate is best

Đất

A light mix that holds water but stays airy: pure live sphagnum, or sphagnum with pumice, perlite or gravel. Examples from experienced growers: 2 parts chopped long-fiber sphagnum, 1 part peat, 1 part fine orchid bark and 2 parts washed pumice; or 1 part peat, 1-2 parts perlite or pumice and 1 part orchid bark. Serpentine gravel is not needed.

pH: Not given; grows on serpentine in the wild

Nhiệt độ

Mùa hè: Keep the soil below 80°F (27°C)

Mùa đông: Cold; survives freezing when fully dormant

Yêu cầu ngủ đông: Like other temperate pitcher plants, the cobra lily needs a cold winter rest of about three to five months in which growth stops. In hard winters plants die back to the rhizome; in mild winters they keep their leaves. Fully dormant plants can survive being frozen solid if the rhizomes are not exposed, but where hard freezes last for weeks, protect them in a cold frame or under a deep mulch. Coastal plants seem to need less winter cold than those from snowy, high-elevation sites.

Cho ăn

Tính thường xuyên: Not needed; never fertilize the soil

Do not fertilize the soil; unlike Sarracenia, the plant does not appear to benefit. Injecting dilute, urea-free fertilizer into the pitchers can help, provided it does not burn the leaves.

Sự lan truyền

Phương pháp: Stolons: when a small plant appears at the tip of a stolon in spring, cut the stolon into sections a few inches long with some roots and lay them on cool, moist long-fiber sphagnum in bright, humid conditions. Division of clumps. Seed, which needs about four weeks of damp, cold stratification and then 2-4 years in the seedling pot.

Khó khăn: Moderate

Mẹo cho người mới bắt đầu

Before buying, make sure you can keep the roots cool in summer. Water from the top with cold pure water every morning and never fertilize the soil.

Xử lý sự cố

A plant that shrinks year after year, or collapses in hot weather starting with the growth points at the edge of the pot, has roots that are too warm. Cool the soil with cold pure water, larger pots or shade on the pot. Tissue-culture plants often grow vigorously at first and then decline.

Mẹo trồng trọt

Why plants shrink Troubleshooting

A cobra lily that gets smaller each year usually has roots that are too warm, often in stagnant soil. Switch to an airier mix and cooler, more frequent watering.

Start new plants from stolons Advanced

When a baby plant shows at the end of an underground runner, cut the runner into short rooted pieces and lay them on moist sphagnum in a bright, humid spot.

Cool roots, warm leaves Seasonal

In the wild, cold spring water flows past the roots. In summer keep the soil below 27°C (80°F) with cold top watering, ice cubes of pure water or a shaded pot.

Sự thật thú vị

Its roots are extremely heat-sensitive and die back after exposure to temperatures not much higher than 10°C (50°F), even where summer air passes 25°C (77°F).
Removing the forked 'tongue' does not reduce the amount of prey caught.
A tiny mite, Sarraceniopus darlingtoniae, lives only in its pitchers, moving to new pitchers each spring.
Its pollinator was long a mystery; a 2011 study found the mining bee Andrena nigrihirta pollinating it.
The anthocyanin-free form f. viridiflora is also grown as the cultivar 'Othello'.
It holds the Royal Horticultural Society's Award of Garden Merit.

Lịch sử

The plant was discovered in 1841 near Mount Shasta in northern California by the botanist William Dunlop Brackenridge during the Wilkes Expedition. In 1853 John Torrey described it, naming the genus after the Philadelphia botanist William Darlington (1782-1863). A popular story that Brackenridge found it while being pursued by Native Americans is a legend. In 1891 the genus name Chrysamphora was proposed for the plant, but it was later rejected as superfluous.

The anthocyanin-free form was described as f. viridiflora by Barry Rice, who earlier gave it the cultivar name 'Othello'. The IUCN Red List assessment, from 2000, classes the species as Least Concern, while NatureServe rates it Vulnerable. Threats noted by Barry Rice include land development, fire suppression, grazing, the root-rot disease killing Port Orford cedar along its streams, the invasive shrub Cytisus scoparius and possible future nickel mining on serpentine.

Nguồn

Câu hỏi thường gặp

Strong light; full sun if it does not overheat the plant. Indoors or for seedlings, give as much LED light as possible without making the plants hot. Plants in humid, warm places can take sun; where humidity is low or variable, part shade suits them better. Nhắm tới khoảng Full sun in season ánh sáng mỗi ngày.

Pure water (distilled or reverse osmosis), as cool as possible. Water from above, regularly, ideally in the early morning when water is coolest; many growers water every day. Tall pots may stand in a few centimeters of water, but avoid stagnant, stinky soil, which leads to root rot. In hot weather growers place ice cubes of pure water on the soil, pump cooled water through the pots, or keep pots in the ground or in shaded, deep trays to hold the roots cool.

A light mix that holds water but stays airy: pure live sphagnum, or sphagnum with pumice, perlite or gravel. Examples from experienced growers: 2 parts chopped long-fiber sphagnum, 1 part peat, 1 part fine orchid bark and 2 parts washed pumice; or 1 part peat, 1-2 parts perlite or pumice and 1 part orchid bark. Serpentine gravel is not needed.

Like other temperate pitcher plants, the cobra lily needs a cold winter rest of about three to five months in which growth stops. In hard winters plants die back to the rhizome; in mild winters they keep their leaves. Fully dormant plants can survive being frozen solid if the rhizomes are not exposed, but where hard freezes last for weeks, protect them in a cold frame or under a deep mulch. Coastal plants seem to need less winter cold than those from snowy, high-elevation sites.

Do not fertilize the soil; unlike Sarracenia, the plant does not appear to benefit. Injecting dilute, urea-free fertilizer into the pitchers can help, provided it does not burn the leaves. Tần suất: Not needed; never fertilize the soil.

Northern California and southwestern Oregon, north along the Oregon coast to Tillamook County, USA. The cobra lily is restricted to places with year-round water flow: fens, seeps, sphagnum bogs, stream and pond margins and dripping cliff faces, from the seacoast to near-alpine elevations.

Sách Đỏ IUCN đánh giá loài này ở mức Least Concern.

Stolons: when a small plant appears at the tip of a stolon in spring, cut the stolon into sections a few inches long with some roots and lay them on cool, moist long-fiber sphagnum in bright, humid conditions. Division of clumps. Seed, which needs about four weeks of damp, cold stratification and then 2-4 years in the seedling pot.

A plant that shrinks year after year, or collapses in hot weather starting with the growth points at the edge of the pot, has roots that are too warm. Cool the soil with cold pure water, larger pots or shade on the pot. Tissue-culture plants often grow vigorously at first and then decline.

Loài này phù hợp hơn với người trồng đã có kinh nghiệm, vì điều kiện của nó khó tái tạo ở nhà.

Carnivoras bán Cobra Lily tại Mexico. Xem các cây đang có sẵn trên trang này.