Whitetop | |
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Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Eudicots |
Clade: | Rosids |
Order: | Brassicales |
Family: | Brassicaceae |
Genus: | Lepidium |
Species: | L. draba |
Binomial name | |
Lepidium draba | |
Subspecies | |
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Synonyms | |
Cardaria draba(L.) Desv. |
Lepidium draba, also known as whitetop, hoary cress, [1] or Thanet cress, [2] is a rhizomatous perennial flowering plant in the family Brassicaceae. It is native to western Asia and southeastern Europe and has been widely introduced elsewhere.
Whitetop is a perennial herb that reproduces by seeds and by horizontal creeping roots. [3] The stem is stoutish, erect or spreading, 10 to 80 cm tall, branched, covered sparsely with ash-colored soft hairs to heavily covered. The leaves are alternating, simple, and mostly toothed. The basal leaves are 4 to 10 cm, have a slight stem (petiole), and are long and flat, lance-shaped to egg-shaped, with the narrow end attached to the stalk. [4] On the upper part of the stem the leaves are attached directly to the stalk (sessile), are 2 to 6.5 cm long, and are oblong or tapering the point, with broad bases that clasp the stalk. [5] Whitetop has slightly domed flower clusters in which the individual flower stalks grow upward from various points off the branch to approximately the same height (corymb-like). The petals are white, clawed, and 3 to 5 mm long, about twice the length of the sepals. Typically, each flower has four petals. [4] [6]
Hoary cress was traditionally used for medicinal purposes, including anti-inflammatory and antibacterial treatments. [4]
It is native to western Asia and southeastern Europe and is an invasive species in North America, introduced by contaminated seeds in the early 1900s. Also known as Cardaria draba, hoary cress is a weed in much of south-east and south-west Australia as well. [7] [8] It has been suggested that native grasses from the Poa genera may be able to outcompete hoary cress in North America. [9]
Ficaria verna, commonly known as lesser celandine or pilewort, is a low-growing, hairless perennial flowering plant in the buttercup family Ranunculaceae native to Europe and Western Asia. It has fleshy dark green, heart-shaped leaves and distinctive flowers with bright yellow, glossy petals. It is now introduced in North America, where it is known by the common name fig buttercup and considered an invasive species. The plant is poisonous if ingested raw and potentially fatal to grazing animals and livestock such as horses, cattle, and sheep. For these reasons, several US states have banned the plant or listed it as a noxious weed. It prefers bare, damp ground and is considered by horticulturalists in the United Kingdom as a persistent garden weed; nevertheless, many specialist plantsmen, nursery owners and discerning gardeners in the UK and Europe collect selected cultivars of the plant, including bronze-leaved and double-flowered ones. Emerging in late winter with flowers appearing late February through May in the UK, its appearance across the landscape is regarded by many as a harbinger of spring.
Allium vineale is a perennial, bulb-forming species of wild onion, native to Europe, northwestern Africa and the Middle East. The species was introduced in Australia and North America, where it has become a noxious weed.
Lepidium latifolium, known by several common names including perennial pepperweed, broadleaved pepperweed, pepperwort, or peppergrass, dittander, dittany, and tall whitetop, is a perennial plant that is a member of the mustard and cabbage family.
Cirsium arvense is a perennial species of flowering plant in the family Asteraceae, native throughout Europe and western Asia, northern Africa and widely introduced elsewhere. The standard English name in its native area is creeping thistle. It is also commonly known as Canada thistle and field thistle.
Lepidium is a genus of plants in the mustard/cabbage family, Brassicaceae. The genus is widely distributed in the Americas, Africa, Asia, Europe, and Australia. It includes familiar species such as garden cress, maca, and dittander. General common names include peppercress, peppergrass, pepperweed, and pepperwort. Some species form tumbleweeds. The genus name Lepidium is a Greek word meaning 'small scale', which is thought to be derived from a folk medicine usage of the plant to treat leprosy, which cause small scales on the skin. Another meaning is related to the small scale-like fruit.
Lepidium campestre, the field pepperwort, field peppercress, field peppergrass, field pepperweed or field cress, is usually a biennial with some form of annual plant in the Brassicaceae or mustard family, native to Europe, but commonly found in North America as an invasive weed. The most notable characteristic of field pepperweed is the raceme of flowers which forks off of the stem. These racemes are made up of first small white flowers and later green, flat and oval seedpods each about 6 mm long and 4 mm wide. Each seedpod contains two brown, 2.5 mm long seeds.
Cardamine hirsuta, commonly called hairy bittercress, is an annual or biennial species of plant in the family Brassicaceae, and is edible as a salad green. It is common in moist areas around the world.
Ranunculus acris is a species of flowering plant in the family Ranunculaceae, and is one of the more common buttercups across Europe and temperate Eurasia. Common names include meadow buttercup, tall buttercup, common buttercup and giant buttercup.
Ipomoea cairica is a vining, herbaceous, perennial plant with palmate leaves and large, showy white to lavender flowers. A species of morning glory, it has many common names, including mile-a-minute vine, Messina creeper, Cairo morning glory, coast morning glory and railroad creeper. The species name cairica translates to "from Cairo", the city where this species was first collected.
Cabomba caroliniana, commonly known as Carolina fanwort and various other names, is an aquatic perennial herbaceous plant native to North and South America. Having been a popular aquarium plant, it has been exported around the world, and has become an invasive species in Europe and Australia.
Veronica serpyllifolia, the thyme-leaved speedwell or thymeleaf speedwell, is a perennial flowering plant in the plantain family. It is native to Europe, but can be found elsewhere on most continents as an introduced species.
Lepidium densiflorum is a species of flowering plant in the mustard family known by the common names common pepperweed, prairie peppergrass, elongate peppergrass, hairy-fruited peppergrass, and large-fruited peppergrass.
Lepidium didymum, the lesser swine-cress, is a species of flowering plant in the family Brassicaceae.
Ludwigia peploides is a species of flowering plant in the evening primrose family known by the common names floating primrose-willow and creeping water primrose. It is native to Australia, New Zealand, North America, and South America, but it can be found on many continents and spreads easily to become naturalized. It is well known as a troublesome aquatic noxious weed that invades water ecosystems and can clog waterways. This is perennial herb which grows in moist to wet to flooded areas. The stem can creep over 2 meters long, sometimes branching. It spreads to form mats on the mud, or floats ascending in the water. The leaves are several centimeters long and are borne in alternately arranged clusters along the stem. The flower has 5 to 6 lance-shaped sepals beneath a corolla of 5 or 6 bright yellow petals up to 2.4 centimeters long. The fruit is a hard, cylindrical capsule.
Oxalis latifolia is a species of flowering plant in the woodsorrel family known by the common names garden pink-sorrel and broadleaf woodsorrel. It is native to Mexico and parts of Central and South America.
Cryptostegia is a genus of flowering plants native to tropical Africa and Madagascar. The genus is in the family Apocynaceae.
Lepidium heterophyllum,, is a species of flowering plant in the mustard family which is native to parts of western Europe, growing in shingle banks, wasteland or cultivated fields.
Lepidium coronopus,, is a species of flowering plant in the mustard family which is native to parts of Africa, western Asia and Europe, growing in shingle banks, wasteland or cultivated fields.
Phyla canescens is a species of perennial herbaceous plant in the family Verbenaceae, native to South America. It has been introduced to Australia as an ornamental plant and low-maintenance lawn, but has become naturalised and is considered a serious environmental weed. It is known by several common names including carpet weed, Condamine couch, Condamine curse, fog fruit, frog fruit, hairy fogfruit, lippia, mat grass and no-mow grass.
Agriculture Research Service (1970) "Cardaria draba (L.) Deav." Selected Weeds of the United States Agriculture Research Service United States Department of Agriculture, Washington, DC, p. 200