A cactus is a member of the plant family Cactaceae, a family comprising about 127 genera with some 1750 known species of the order Caryophyllales. The word "cactus" derives, through Latin, from the Ancient Greek κάκτος, kaktos, a name originally used by Theophrastus for a spiny plant whose identity is now not certain. Cacti occur in a wide range of shapes and sizes. Most cacti live in habitats subject to at least some drought. Many live in extremely dry environments, even being found in the Atacama Desert, one of the driest places on earth. Cacti show many adaptations to conserve water. Almost all cacti are succulents, meaning they have thickened, fleshy parts adapted to store water. Unlike many other succulents, the stem is the only part of most cacti where this vital process takes place. Most species of cacti have lost true leaves, retaining only spines, which are highly modified leaves. As well as defending against herbivores, spines help prevent water loss by reducing air flow close to the cactus and providing some shade. In the absence of leaves, enlarged stems carry out photosynthesis. Cacti are native to the Americas, ranging from Patagonia in the south to parts of western Canada in the north—except for Rhipsalis baccifera, which also grows in Africa and Sri Lanka.
Protea cynaroides, the king protea, is a flowering plant. It is a distinctive member of Protea, having the largest flower head in the genus. The species is also known as giant protea, honeypot or king sugar bush. It is widely distributed in the southwestern and southern parts of South Africa in the fynbos region.
Begonia is a genus of perennial flowering plants in the family Begoniaceae. The genus contains more than 1,800 different plant species. The Begonias are native to moist subtropical and tropical climates. Some species are commonly grown indoors as ornamental houseplants in cooler climates. In cooler climates some species are cultivated outside in summertime for their bright colorful flowers, which have sepals but no petals.
A vine is any plant with a growth habit of trailing or scandent stems, lianas or runners. The word vine can also refer to such stems or runners themselves, for instance, when used in wicker work.
Bulbophyllum is a genus of mostly epiphytic and lithophytic orchids in the family Orchidaceae. It is the largest genus in the orchid family and one of the largest genera of flowering plants with more than 2,000 species, exceeded in number only by Astragalus. These orchids are found in diverse habitats throughout most of the warmer parts of the world including Africa, southern Asia, Latin America, the West Indies, and various islands in the Indian and Pacific Oceans. Orchids in this genus have thread-like or fibrous roots that creep over the surface of trees or rocks or hang from branches. The stem is divided into a rhizome and a pseudobulb, a feature that distinguished this genus from Dendrobium. There is usually only a single leaf at the top of the pseudobulb and from one to many flowers are arranged along an unbranched flowering stem that arises from the base of the pseudobulb. Several attempts have been made to separate Bulbophyllum into smaller genera, but most have not been accepted by the World Checklist of Selected Plant Families.
Dendrobium is a genus of mostly epiphytic and lithophytic orchids in the family Orchidaceae. It is a very large genus, containing more than 1,800 species that are found in diverse habitats throughout much of south, east and southeast Asia, including China, Japan, India, the Philippines, Indonesia, Australia, New Guinea, Vietnam and many of the islands of the Pacific. Orchids in this genus have roots that creep over the surface of trees or rocks, rarely having their roots in soil. Up to six leaves develop in a tuft at the tip of a shoot and from one to a large number of flowers are arranged along an unbranched flowering stem. Several attempts have been made to separate Dendrobium into smaller genera, but most have not been accepted by the World Checklist of Selected Plant Families.
Tsuga is a genus of conifers in the subfamily Abietoideae. The common name hemlock (tree) is derived from a perceived similarity in the smell of its crushed foliage to that of the unrelated plant poison hemlock. Unlike the latter, Tsuga species are not poisonous.
Hypericum is a genus of flowering plants in the family Hypericaceae. The genus has a nearly worldwide distribution, missing only from tropical lowlands, deserts and polar regions. Many Hypericum species are regarded as invasive species and noxious weeds. All members of the genus may be referred to as St. John's wort, and some are known as goatweed. The white or pink flowered marsh St. John's worts of North American and eastern Asia are now separated into the genus Triadenum.
Juncaceae is a family of flowering plants, commonly known as the rush family. It consists of 8 genera and about 464 known species of slow-growing, rhizomatous, herbaceous monocotyledonous plants that may superficially resemble grasses and sedges. They often grow on infertile soils in a wide range of moisture conditions. The best-known and largest genus is Juncus. Most of the Juncus species grow exclusively in wetland habitats. A few rushes, such as Juncus bufonius are annuals, but most are perennials.
In biological classification, especially zoology, the type genus is the genus which defines a biological family and the root of the family name.
A lamella, or gill, is a papery hymenophore rib under the cap of some mushroom species, most often but not always agarics. The gills are used by the mushrooms as a means of spore dispersal, and are important for species identification. The attachment of the gills to the stem is classified based on the shape of the gills when viewed from the side, while color, crowding and the shape of individual gills can also be important features. Additionally, gills can have distinctive microscopic or macroscopic features. For instance, Lactarius species typically seep latex from their gills.
Schlumbergera is a small genus of cacti with six to nine species found in the coastal mountains of south-eastern Brazil. Plants grow on trees or rocks in habitats that are generally shady with high humidity, and can be quite different in appearance from their desert-dwelling cousins. Most species of Schlumbergera have stems which resemble leaf-like pads joined one to the other and flowers which appear from areoles at the joints and tips of the stems. Two species have cylindrical stems more similar to other cacti. Recent phylogenetic studies using DNA have led to three species of the related genus Hatiora being transferred into Schlumbergera, though this change is not universally accepted.
The genus Scrophularia of the family Scrophulariaceae comprises about 200 species of herbaceous flowering plants commonly known as figworts. Species of Scrophularia all share square stems, opposite leaves and open two-lipped flowers forming clusters at the end of their stems. The genus is found throughout the Northern Hemisphere.
In mycology, a partial veil is a temporary structure of tissue found on the fruiting bodies of some basidiomycete fungi, typically agarics. Its role is to isolate and protect the developing spore-producing surface, represented by gills or tubes, found on the lower surface of the cap. A partial veil, in contrast to a universal veil, extends from the stem surface to the cap edge. The partial veil later disintegrates, once the fruiting body has matured and the spores are ready for dispersal. It might then give rise to a stem ring, or fragments attached to the stem or cap edge. In some mushrooms, both a partial veil and a universal veil may be present.
Cooksonia is an extinct grouping of primitive land plants. The earliest Cooksonia date from the middle of the Silurian ; the group continued to be an important component of the flora until the end of the Early Devonian, a total time span of 433 to 393 million years ago. While Cooksonia fossils are distributed globally, most type specimens come from Britain, where they were first discovered in 1937. Cooksonia includes the oldest known plant to have a stem with vascular tissue and is thus a transitional form between the primitive non-vascular bryophytes and the vascular plants.
Cortinarius is a globally distributed genus of mushrooms in the family Cortinariaceae. It is suspected to be the largest genus of agarics, containing over 2,000 widespread species. A common feature among all species in the genus Cortinarius is that young specimens have a cortina (veil) between the cap and the stem, hence the name, meaning curtained. Most of the fibres of the cortina are ephemeral and will leave no trace once gone, except for limited remnants on the stem or cap edge in some species. All have a rusty brown spore print. The common names cortinar and webcap refer to members of the genus. Due to dangerous toxicity of several species and the fact that it is difficult to distinguish between various species of the genus, non-expert consumption of mushrooms from the genus is discouraged.
In botany, the petiole is the stalk that attaches the leaf blade to the stem, and is able to twist the leaf to face the sun. This gives a characteristic foliage arrangement to the plant. Outgrowths appearing on each side of the petiole in some species are called stipules. Leaves lacking a petiole are called sessile or apetiolate.
Habenaria, commonly called rein orchids or bog orchids, is a widely distributed genus of orchids in the tribe Orchideae. About 880 species of Habenaria have been formally described. They are native to every continent except Antarctica, growing in both tropical and subtropical zones.
Anulocaulis annulatus is a species of flowering plant in the four o'clock family known by the common name valley ringstem. It is endemic to the Mojave Desert of California, especially in the vicinity of Death Valley. This is a perennial herb growing a number of thin, erect stems sometimes exceeding a meter in height from a thick caudex.
Leucospermum cuneiforme is an upright evergreen shrub with many pustules growing on the lower branches, wedge-shaped leaves, and oval, initially yellow flower heads that later turn orange, with long styles sticking far beyond the perianths, jointly giving the impression of a pincushion. It is called wart-stemmed pincushion in English and luisiesbos (lice-bush) in Afrikaans. The species is common in the southern mountains of South Africa.
