Carnivorous plants

 

 

 

 

 

 

 

 

 

 

 

 

Most species are climbers, often several metres long. The midrib of the leaf is prolonged into a tendril, which forms a globe- or tube-shaped pitcher. Usually, two types of pitchers are produced, larger ones near the ground, and smaller ones higher up. The ‘lip’, or peristome, around the upper edge of the pitcher is very slippery, causing tiny animals to slide into the trap. The fluid in the pitcher is viscoelastic, causing winged insects to be unable to escape. Along the inner edge is a row of stiff, down-pointing hairs, which prevent prey from escaping. Above the peristome is an umbrella-like cover, the operculum, the purpose of which is to prevent excess rainfall into the pitcher.

The generic name attests to the imaginative mind of Swedish naturalist Carl Linnaeus (1707-1778). It is derived from Ancient Greek ne (‘not’) and penthos (‘grief’), thus ‘relieving grief’. This term was used by Homer in the Odyssey to describe a fictional drug that could relieve sorrow. Linnaeus adopted the name for these plants due to their striking and captivating nature, indicating that they might have a similar effect on those who observed them.

 

The specific name is derived from the Latin destillo (‘to distill’), and the suffix oria, thus an approximate translation might be ‘something from which a liquid is distilled’, i.e. a container, naturally referring to the pitcher-like tip of the leaf.

In 1677, Danish physician, mathematician, and theologian Thomas Bartholin (1616-1680) mentioned it briefly under the name Miranda herba (‘marvelous herb’). It was again described in 1683 by Swedish physician and naturalist Herman Niklas Grim (1641-1711), who wrote several works on plants in Asia and southern Africa.

Grim called it Planta mirabilis destillatoria (‘the miraculous distilling plant’), and in 1686 English naturalist John Ray (1627-1705) quoted Grim as saying: “The root draws up moisture from the earth, which with the help of the sun’s rays rises up into the plant itself and then flows down through the stems and nerves of the leaves into the natural utensil to be stored there until used for human needs.”

 

 

 

 

 

The stem is to 3 m long, having a diameter of up to 5 mm, leaves sessile, blade lanceolate or elliptic, to 15 cm long and 3 cm wide, the base clasping the stem, tendril to 15 cm long. The pitcher is slender, usually below 15 cm tall and 3 cm wide, occasionally larger. Lower pitchers are ovoid below and cylindrical above, whereas upper pitchers are cylindrical. A pair of fringed wings runs down the front of lower pitchers, often reduced to ribs on upper pitchers. The operculum is ovate, often with many hair-like appendages above (see picture), but these are lacking in some forms of the plant.

It was described in 1873 by the famous British botanist Joseph Dalton Hooker (1817-1911) in his monograph Nepenthaceae.

The specific name is derived from the Latin tentacula (‘tentacles’), alluding to the appendages on the upper surface of the operculum.

 

 

 

 

 

The stem may grow to 8 m long, with a diameter of 1 cm, but it rarely climbs higher than 60 cm above the forest floor. The stalked leaves are oblong or spatulate, to 25 cm long and 6 cm wide, and the tendrils may be up to 50 cm long. The barrel-shaped pitchers may be up to 25 cm long and 9 cm wide, with two fringed wings running down the front.

The specific name is Latin, meaning ‘hairy’, referring to the fringed wings on the pitcher.

 

 

 

 

 

 

 

 

 

Like Nepenthes, these plants are equipped with a slippery peristome, and an operculum. As they are not closely related, this is an example of convergent evolution.

 

It is distributed from southern Virginia southwards through the Carolinas to Georgia, Alabama, and Florida. It is widely cultivated in Europe, and populations are often illegally planted in marshes, where they tend to become invasive, if they are not controlled in time. Escaped or planted populations are also found in California.

The specific name is Latin, meaning ‘yellow’.

 

 

 

 

 

 

 

 

 

 

 

It is restricted to south-eastern United States, found from southern North Carolina southwards to central Florida.

This plant is rather small, which is reflected in the specific name.

 

 

 

 

 

It is the most widely distributed member of the genus, found in most of southern Canada, in the Great Lakes area, and in easternmost United States, southwards to South Carolina. It is the official flower of Newfoundland and Labrador.

Like yellow pitcher plant, this species is widely cultivated in Europe and elsewhere, and populations are sometimes illegally planted in marshes (see picture above at yellow pitcher plant).

 

 

 

 

 

It was discovered in 1841, and in 1853 it was described by American botanist, chemist, and physician John Torrey (1796-1873), who named it Darlingtonia in honour of botanist William Darlington (1782-1863) of Philadelphia.

Fragrance from nectar, emitted by the plant, lures insects into the long, tube-shaped pitchers, which are filled with fluid.

 

 

 

 

 

 

 

 

 

 

The genus contains about 125 species and is widely distributed in subarctic and temperate regions of the Northern Hemisphere, and also in Central and South America.

The generic name is diminutive of the Latin pinguis (‘fat’ – compare the word ‘penguin’), which, like the common name butterwort, refers to the slimy and fatty leaves.

 

 

 

 

 

 

 

 

 

 

 

 

 

The specific name refers to the leaf shape.

 

 

 

 

 

Formerly, the slime of the leaves was applied to cracks on cow udders. During an excursion in 1747, an apprentice of Swedish naturalist Carl Linnaeus (1707-1778), says that ”in Switzerland, Pinguicula is used externally on fissuris mammarum, even if the udder becomes hardened, so that it will milk blood.”

In the old days, in large parts of northern Europe, a common practice was to apply leaves of butterwort to milk to make it separate or thicken. German farmers would place butterwort plants in water, later using this water to make tough or newly cut meat tender.

In folk medicine, the plant has mostly been used to heal wounds and various skin problems. In Denmark, in the 1900s, when many children were suffering from ringworm and other skin ailments, the affected parts were smeared with butter, or leaves of butterwort.

In his thesis from 1688, De usu plantarum, Danish herbalist Ole Borch recommends butterwort for treatment of hectica febris legitima (‘true consumption’) and hernias. He states that ”you must apply a compress of milk, mixed with moss or butterwort roots on the affected parts, not only for healing, but also to give it back its natural humidity.”

In the old days, in Denmark, farmers were convinced that if sheep would consume butterwort “before Michaelmas” (September 29), they would get liver flukes (Distoma hepaticum). However, the biological explanation is that the sheep got these parasites by grazing in wet areas, where not only butterwort thrives, but also the flukes.

The specific name is Latin, meaning ‘common’.

 

 

 

 

 

 

 

These plants capture small animals by means of bladder-like traps. The pressure inside the bladder is negative, compared to its surroundings. When trigger hairs on the trapdoor is touched by a tiny animal, the prey, along with the water around it, is sucked into the bladder, whereupon the door closes again, the whole procedure lasting only 1/10,000th of a second.

The flowers of the aquatic species are arranged at the end of a stalk, protruding from the water. They are two-lipped, yellow in most species.

The genus also contains terrestrial species, which mainly grow in humid soil and moss. Whereas aquatic species catch larger prey like water fleas and nematodes, terrestrial species catch tiny organisms like protozoa and rotifers.

 

The deep yellow flowers are arranged in clusters, sometimes up to 10.

The specific name, meaning ‘southern’, refers to the fact that this species was described from a specimen, which was collected in Australia in 1810.

 

 

 

 

 

The leaves are short-stalked, blade kidney-shaped, to 6 mm across, margin entire. The bladders are stalked, ovoid, about 1 mm long, tip blunt. The flowering stems are to 8 cm tall, with single or paired flowers, to 8 mm long, corolla white, often with violet streaks on the upper lip, and a yellow spot at the the base of the lower lip, which is rounded, 3- or 5-lobed, spur cylindric, to 4 mm long. Calyx lobes to 4 mm long, purple or violet. Flowering occurs July-September.

It is distributed at altitudes between 1,500 and 4,200 m, found from central Nepal eastwards to the Chinese provinces Sichuan and Yunnan.

The specific name is derived from the Latin bracchium (‘arm’ or ‘limb’) and the suffix atus, thus ‘having branches resembling arms’, presumably alluding to the occasional twin branches on the flowering stem.

 

 

 

 

 

The specific name refers to the inflated leafstalks.

 

 

 

 

 

The specific name is derived from Ancient Greek makros (‘large’ or ‘long’) and rhiza (‘root’).

 

 

 

 

 

 

 

 

 

 

 

Members of this genus obtain the major part of their nutrients by catching small invertebrates by means of sticky glandular hairs on their leaves. When an animal gets stuck in the sticky juice from these glands, the leaf envelops the unfortunate victim, whereupon enzymes dissolve its body juices, making nitrogen and other nutrients available for the plant.

The generic name is derived from Ancient Greek drosos (‘dew’), referring to the sticky glandular hairs on the leaves, which resemble dew drops, when the sun is shining on them. Formerly, in European folk medicine, dew drops were said to possess miraculous qualities, and the glandular ‘drops’ of sundew were sold as Virgin Mary’s tears. Supposedly, they were able to cure skin diseases like warts, ringworms, and corns, besides many other ailments.

In the old days, in Denmark, farmers were convinced that if sheep would consume sundew “before Michaelmas” (September 29), they would get liver flukes (Distoma hepaticum). The real cause for the sheep to get these parasites was that they were grazing in wet areas, where not only these plants thrive, but also the flukes.

 

It resembles oblong-leaved sundew (below), but the leaves are longer and more slender.

The specific name is the Latin word for ‘English’. The plant was first described from a specimen collected in England.

 

 

 

 

 

The specific name refers to the leaves, whose form is intermediate between those of English sundew (above) and round-leaved sundew (below).

 

 

 

 

 

 

 

Stem erect, branched, sometimes to 50 cm tall, but usually lower. The basal leaves are in a rosette, short-stalked, yellowish-green, rounded. They are sometimes absent. Stem leaves are long-stalked, yellowish-green, crescent-shaped, to 3 cm long and 5 mm broad, upperside with many sticky glands. The stalked flowers are arranged in few- or many-flowered terminal clusters, to 6 cm long. Petals usually 5, white (rarely pink or red), wedge-shaped, to 6 mm long and 3 mm wide. The flowering period is from June to September.

In Nepal, a paste of the leaves is applied to blisters.

The specific name is derived from the Latin pelta, the classical term for a small crescent-shaped shield, like the common name referring to the leaf shape. The alternative specific name, derived from the Latin luna (‘moon’), also refers to the leaf shape (a half-moon).

 

 

 

 

 

The specific name is Latin, meaning ‘with round leaves’.

 

 

 

 

 

It was described in 1759 by North Carolina governor Arthur Dobbs (1689-1765), who wrote: “But the great wonder of the vegetable kingdom is a very curious unknown species of sensitive; it is a dwarf plant; the leaves are like a narrow segment of a sphere, consisting of two parts, like the cap of a spring purse, the concave part outwards, each of which falls back with indented edges (like an iron spring fox trap); upon any thing touching the leaves, or falling between them, they instantly close like a spring trap, and confine any insect or any thing that falls between them; it bears a white flower: to this surprising plant I have given the name of ‘Fly Trap Sensitive’.”

Venus flytrap was highly praised by Swedish naturalist Carl Linnaeus (1707-1778), who called it a “miraculum naturæ”, and by British naturalist Charles Darwin (1809-1882), who labelled it “one of the most wonderful plants of the world.”

This species is unique among flesh-eating plants in having highly modified leaves, which act like a snap-trap, when stimulated in a certain way. On the inner surface of the trap are three stiff hairs, and two of these must be stimulated within a short period of time to trigger the trap. This mechanism has been developed to prevent the plant from using energy on shutting the trap, if e.g. a withered leaf by chance falls into it. Thick, stiff protrusions, or cilia, along the edge of the trap form ’bars’, which prevent prey from escaping.

The specific name is derived from the Latin musca (‘fly’), decipio (‘to catch’ or ‘to trap’), and the suffix ula, thus ‘flytrap’.

 

 

 

 

 

 

 

 

 

 

 

 

Portuguese sundew is one of the few carnivorous plants, which is able to thrive on dry, alkaline soils. The leaves, which are 20 to 40 cm long, uncoil from a central rosette. The plant emits a sweet aroma, which attracts insects. When they land on a leaf, or on the stem, they get stuck in the numerous sticky glandular hairs. There are two types of glands, larger stalked ones, which attract and trap prey, and smaller, sessile, digestive ones.

The generic name is derived from Ancient Greek drosos (‘dew’) and phyllon (‘leaf’), referring to the sticky glands on the leaves, which resemble dew drops. The specific name is derived from Lusitania, the classical Roman name for Portugal.