Sarracenia ( or ) is a genus comprising 8 to 11 species of North American , commonly called trumpet pitchers. The genus belongs to the family Sarraceniaceae, which also contain the closely allied genera Darlingtonia and Heliamphora.
Sarracenia is a genus of carnivorous plants indigenous to the eastern seaboard of the United States, Texas, the Great Lakes area and southeastern Canada, with most species occurring only in the south-east United States (only S. purpurea occurs in cold-temperate regions). The plant's leaves have evolution into a funnel or pitcher shape in order to trap .
The plant attracts its insect prey with secretions from extrafloral nectaries on the lip of the pitcher leaves, as well as a combination of the leaves' color and scent. Slippery footing at the pitcher's rim causes insects to fall inside, where they die and are digested by the plant with and other enzymes.
The inside of the pitcher tube, depending on the species, can be divided into three to five distinguishable zones: zone 1 is the operculum (or hood), zone 2 is the peristome and rest of the trap entrance, while zones 3 and 4 (which in some species are combined) and 5 (only present in S. purpurea) are further divisions of the actual tube. Each of these zones has a specific function, with corresponding morphophysiological characteristics.
Most species use a combination of scent, waxy deposits (to clog insect feet) and gravity to topple insect prey into their pitcher. Once inside, the insect finds the footing very slippery with a waxy surface covering the walls of the pitcher. Further down the tube, downward-pointing hairs make retreat impossible, and in the lowest region of the tube, a pool of liquid containing digestive enzymes and wetting agents quickly drowns the prey and begins digestion. The exoskeletons are usually not digested, and over the course of the summer fill up the pitcher tube.
Only S. purpurea normally contains significant amounts of rainwater in its tubular pitchers. It is a myth that all species contain water. In fact, the hoods of the other species help to keep out rain water in addition to keeping flying prey from escaping.
S. psittacina, the parrot pitcher, uses a Lobster trap style trap that will admit prey (including and small fish during floods) but not allow it to find its way out; and sharp inward-pointing hairs force the victim gradually down to the base of the pitcher where it is digested.
Floral formula: Ca5 Co5 A∞ G(5)
The flowers of almost all species are scented. The scent varies, but is often strong and sometimes unpleasant. S. flava has an especially strong odor resembling cat urine.
Flowers generally last about two weeks. At the end of the flowering period, the petals drop and the ovary, if pollinated, begins to swell. The seed forms in five lobes, with one lobe producing significantly smaller numbers of seeds than the other lobes. On average, 300–600 seed are produced, depending on species and pollination success. Seed takes five months to mature, at which point the seed pod turns brown and splits open, scattering seed. The seeds are 1.5–2 mm in length and have a rough, waxy coat which makes it hydrophobic, possibly for seed dispersal by flowing water. Sarracenia seed requires a stratification period to germinate in large numbers. Plants grown from seed start producing functioning traps almost immediately, although they differ in morphology from adult traps for the first year or so, being simpler in structure. Plants require 3–5 years to reach maturity from seed.
Sarracenia tend to inhabit , herb bogs, and seasonally wet grasslands. These habitats tend to be acidic (low pH) with soil made up of sand and Sphagnum moss. Frequently, the soil will be poor in nutrients, particularly , and often continuously leached by moving water or made unavailable to the plant roots by the low pH. The plants gain their advantage from their ability to extract nutrients from insect prey in this mineral-poor environment. The plants prefer strong, direct sunlight with no shade. Sarracenia habitats in the southeastern Coastal Plain consist primarily of fire-maintained pine savannas, wet prairies, or seepage bogs. Without frequent fire (1–3 years), these habitats undergo ecological succession and are quickly invaded by woody shrubs and trees, which eliminate Sarracenia by increasing shade and reducing soil moisture.
In several cases, carnivorous plant enthusiasts have introduced S. purpurea into suitable habitats outside of its natural range, where it has naturalized. Some of these populations are decades old; the oldest known occurrence in the Swiss Jura mountains is around one hundred years old. Besides Switzerland, such naturalized populations can be found in Ireland, England (Lake District), Germany (Bavaria, Lusatia) and in Mendocino County along the California coast.
Some protective legislation exists. Several southeastern states, such as Florida, Georgia, and South Carolina have conservation laws which protect Sarracenia. However, most of the remaining wetlands in the southeastern U.S. are privately owned. Plants on this land are not protected by state legislation. The key states of Alabama and Mississippi have no such legislation at all, so that even plants on public land have no protection. Three Sarracenia have been listed as "Federally Endangered" under the USA Endangered Species Act (1973) – Sarracenia rubra subsp. alabamensis ( S. alabamensis) in Alabama, S. rubra subsp. jonesii ( S. jonesii) in North Carolina and South Carolina, and S. oreophila in Alabama, Georgia, and North Carolina. These taxa are also on CITES Appendix I, giving them international protection by making export of wild-collected plants illegal. The other species, while appearing on CITES Appendix II, have little federal protection.
Some efforts have been made to curb the existing threats to plants. In 2003 the International Carnivorous Plant Society ran a trial distribution program in which young S. rubra subsp. alabamanensis plants were grown from seed collected from 3 of the 12 known S. alabamanensis sites, and were distributed to members in an attempt to increase availability of this plant in cultivation, with the hopes of thereby decreasing the poaching that was endangering the survival of this taxon in the wild. In 1995, the non-profit organization Meadowview Biological Research Station was created to preserve and restore pitcher plant bogs and associated ecosystems in Maryland and Virginia.
In 2004, a number of concerned plant enthusiasts founded the North American Sarracenia Conservancy (NASC), which aims to "serve as a living record of the taxonomic, morphological and genetic diversity of the genus Sarracenia for purposes of conservation and cultivation." The NASC is a grassroots Nebraska nonprofit organization working to build a genetic Sarracenia bank by overseeing the maintenance of genetic strains from all remaining wild populations in cultivation, with the eventual aim of being able to supply these strains for re-introduction in suitable habitats. A similar but centralized collection exists in the UK, with 2000+ clones representing all species (many with location data) and numerous hybrids currently being housed by Sarracenia expert Mike King. This UK collection is part of the NCCPG National Plant Collection scheme. While none of these efforts curb the biggest threats – urban development and habitat destruction – they aim to help reduce plant poaching while at the same time making these plants available to future generations.
One of the biggest challenges of reintroducing plants back into the wild is the unintended introduction of unwanted species, such as pests, diseases, and invasive weeds. Often, it is human destruction of areas in which the Sarracenia thrive that is a major killer. Aside from determining what genetic material is appropriate for reintroduction (which is up for debate), plants must be semi-aseptic to keep the habitat pristine and sustainable in the long term. Another challenge is maintaining all of the introduced plant material and determining an optimal site to plant them in. A single hurricane or storm event can change the dynamics of a field. Even within a single bog, some areas may be waterlogged, while other areas may become very dry, so identifying the right location is critical. Short term results on private property indicate planting larger specimens into the field have a higher chance of long-term survival compared to planting smaller seedlings.
Typically anywhere from 8 to 11 species of Sarracenia are generally recognized, depending on individual opinions on the biological species concept and which among many subspecies and varieties should be elevated to species status, a common lumping and splitting problem in demarcation.Rice, Barry. (2008). Sarracenia species lists. Sarracenia.com FAQ. Accessed: 10-10-2008. Some authorities split the described subspecific taxa of S. rubra into 3 to 5 species. Similarly, S. rosea is not always recognized as a species distinct from S. purpurea. The most commonly recognized species include:
Alabama, eastern Mississippi and Florida. |
eastern Louisiana across southern Mississippi and into western Alabama and a western range from eastern Texas into western Louisiana. |
southern Alabama, through Florida and Georgia, southern Virginia, North Carolina and South Carolina. |
North Carolina and South Carolina. |
west of the Apalachicola River on the Florida Panhandle. It is also found in Alabama, Georgia, Louisiana, Mississippi, and North Carolina |
northern Florida and in Georgia up to the southern part of North Carolina. |
northern Alabama, North Carolina, Georgia, and—historically—Tennessee |
Louisiana, Alabama, Mississippi, Florida, Georgia |
Eastern seaboard, the Great Lakes region, Canada (except Nunavut and Yukon), Washington state, and Alaska. |
Mississippi to Georgia. |
southern Mississippi, through southern Alabama, the Florida panhandle and Georgia, to the coastal plains of Virginia and South Carolina. |
Currently, S. rubra can be described as having six subspecies, though it is sometimes argued that the subspecies should be elevated to species rank in recognition of the species complex that they are a part of. This division would yield S. alabamensis, S. gulfensis, S. jonesii, S. rubra sensu stricto, S. viatorum, and S. wherryi. Others have argued that only some of these demand recognition at the species rank.Barthlott, W., S. Porembski, R. Seine, and I. Theisen. (2007). The Curious World of Carnivorous Plants. Portland: Timber Press.
Note: The entity McPherson and Schnell referred to as S. rubra "Incompletely diagnosed taxon from Georgia and South Carolina" has since been established as Sarracenia rubra subsp. viatorum B.Rice.
Some of the more common named hybrids include:
The name Sarracenia was first employed by Michel Sarrazin, the Father of Canadian Botany who in the late 17th century sent live specimens of S. purpurea to the Parisian botanist Joseph Pitton de Tournefort, who thereupon described the species. Carl Linnaeus adopted this name when he published his Species Plantarum (1753), using it for the two known species at the time: S. purpurea and S. flava. The first successful flowering in culture occurred in 1773. In 1793 William Bartram noted in his book about his travels in the southeast U.S. that numerous insects were caught in the pitchers of these plants, but doubted that any benefit could be derived from them.
It was not until 1887 that research by Joseph H. Mellichamp proved the carnivorous nature of this genus. This finding was supported by a study by J.S. Hepburn, E.Q. St. John and F.M. Jones in 1920. Extended field surveys and laboratory studies by Edgar Wherry in the 1930s greatly increased the knowledge of this genus, which has further been extended by the more recent works of C. Ritchie Bell (1949–52), Donald E. Schnell (1970–2002), Frederick W. Case (1970–2000s), and T. Lawrence Mellichamp (1980s-2000s).
Sarracenia require constantly moist-wet, nutrient free acidic soil. This is most often achieved with a potting mix consisting of peat moss mixed with sand or perlite. As their roots are sensitive to nutrients and minerals, only pure water, such as distilled, rain, or reverse osmosis water, can be used to water them. Sarracenia prefer sunny conditions during their growing season but require a dormancy period, with decreased light and temperatures, of a few months in the winter.
[[Image:Sarracenia rhizome.JPG|thumb|A Sarracenia rhizome with a few
growing points, capable of division]]The copious seeds store well if kept dry. In climates or seasons that cannot provide the cold, damp period of stratification required by the seeds for germination, growers mimic this condition by placing the seeds in a refrigerator for 2–6 weeks, depending on species. The seeds are sown on the surface of their substrate and germinate when transferred to warmer, bright conditions. Sarracenia seedlings all look alike for the first two or three years; the plants reach maturity after four or five years. Regular fertilization (twice a month between April and September) with a balanced fertilizer at the rate of 1 teaspoon per gallon (using a 15-16-17 peat-lite or similar fertilizer) will speed their growth and time to maturity. It is advisable to leach regularly with pure water to prevent the buildup of solutes (fertilizer salts) in the soil. Deep water in a potted plant keeps the soil too waterlogged for proper root functioning.
Mature Sarracenia are commonly propagated by division. Their rhizomes extend and produce new crowns of pitchers over the course of a few growing seasons, and cultivators divide and separate the rhizomes during the plant's winter dormancy or early in the growing season. This technique is also used to separate sections of rhizomes which have no pitchers: when re-potted, the section usually generates a new crown of pitchers. A further technique is employed to encourage new crowns to appear which does not involve division of the rhizome: small notches up to 5 mm deep are cut into the top of the rhizome, whereupon a new crown frequently develops at the site of the notch.
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