| Orostachys | |
|---|---|
 | |
| Orostachys malacophylla var. iwarenge | |
Scientific classification  | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Order: | Saxifragales |
| Family: | Crassulaceae |
| Tribe: | Telephieae |
| Genus: | Orostachys |
| Species | |
See text. | |
Orostachys is a genus of the succulent family Crassulaceae (stonecrop family) that contains about 15 species. It is a biennial herb growing in China, Japan, Kazakhstan, Korea, Mongolia, Russia. Eight species occur in China. [1]
Orostachys are the most morphologically distinct member of subfamily Sempervivoideae. Orostachys species are mostly biennial herbaceous plants that are more or less succulent. Leaves are linear to ovate, often with dull purple dots. The arrangement is alternate, forming crowded cauline rosettes. Especially the thick-fleshed foliage stores water. The leaf ends have a cartilaginous to spiny, white tip. Leaf margins are usually smooth. Stipules are absent. The roots are fibrous and there is no rhizome.
In the first year, the leaves stand together in solitary, basal, dense rosettes. In the second year, a solitary, leafy stem, 5 to 60 cm in length, arises from the center of the rosette and forms flowers. The terminal inflorescences, usually branched and composed of individual spicate inflorescences, are relatively large and narrowly pyramidal to cylindrical, containing many flowers and foliage-like bracts. The flowers, which are at most very short-stemmed, are hermaphroditic and pentamerous. The free sepals are usually shorter than the petals. The five predominantly yellow, rarely white, yellow-green, or pinkish to reddish petals are almost free. There are two circles with five stamens. The yellowish nectary scales are relatively small. The erect carpels are free and contain many ovules. The styles are narrow.
The many-seeded follicles possess a beak-like end. The seeds are small.
Within family Crassulaceae, Orostachys is placed in tribe Telephieae of subfamily Sempervivoideae. The genus has. at times, included Meterostachys . Molecular phylogenetics shows that the genus is not monophyletic, but polyphyletic with respect to Hylotelephium . Its circumscription, therefore, is unstable and subject to revision. [2]
The genus Orostachys has been divided into series (or sections), including: [2] [3] [4]
Other authors have created two different sections: [5]
Some species were transferred from Sinocrassula into Orostachys, as section Schoenlandia, also treated as a subgenus or section, [3] [2] or a separate genus Kungia , e.g. O. schoenlandii (Kungia schoenlandii). [6] Orostachys section Orostachys, in turn has been treated as two subsections, differing by either flat or fleshy leaf shape, and the presence or absence of appendages on the leaves, which include spines or cartilaginous protrusions: [5]
On the basis of molecular data, it has been proposed that Orostachys subsection Appendiculatae be considered a separate genus. [5]
The genus includes about 12–17 accepted species, including: [6] [3]
The Crassulaceae, also known as the stonecrop family or the orpine family, are a diverse family of dicotyledon flowering plants characterized by succulent leaves and a unique form of photosynthesis, known as Crassulacean acid metabolism (CAM). Flowers generally have five floral parts. Crassulaceae are usually herbaceous but there are some subshrubs, and relatively few treelike or aquatic plants. Crassulaceae are a medium-sized monophyletic family in the core eudicots, among the order Saxifragales, whose diversity has made infrafamilial classification very difficult. The family includes approximately 1,400 species and 34–35 genera, depending on the circumscription of the genus Sedum, and distributed over three subfamilies. Members of the Crassulaceae are found worldwide, but mostly in the Northern Hemisphere and southern Africa, typically in dry and/or cold areas where water may be scarce, although a few are aquatic.
Aeonium, the tree houseleeks, is a genus of about 35 species of succulent, subtropical plants of the family Crassulaceae. Many species are popular in horticulture. The genus name comes from the ancient Greek αἰώνιος / aiōnios (ageless). While most of them are native to the Canary Islands, some are found in Madeira, Cape Verde, Morocco, in East Africa and Yemen.
Sedum is a large genus of flowering plants in the family Crassulaceae, members of which are commonly known as stonecrops. The genus has been described as containing up to 600 species, subsequently reduced to 400–500. They are leaf succulents found primarily in the Northern Hemisphere, but extending into the southern hemisphere in Africa and South America. The plants vary from annual and creeping herbs to shrubs. The plants have water-storing leaves. The flowers usually have five petals, seldom four or six. There are typically twice as many stamens as petals. Various species formerly classified as Sedum are now in the segregate genera Hylotelephium and Rhodiola.
Prometheum is a genus of plants in the family Crassulaceae.
Dudleya, commonly known as liveforevers is a genus of rosette-forming succulent plants in the stonecrop family, Crassulaceae, consisting of about 68 taxa in southwestern North America and Guadalupe Island. The species come in many forms, some large and evergreen, others geophytic and deciduous. Yet, despite their dramatic variations in appearance, most species readily hybridize. The flowers of Dudleya have parts numbered in fives, with the petals arranged in tubular, star-shaped, and bell-shaped forms and, when fruiting, are filled with tiny, ovoid-crescent-shaped seeds.
Bryophyllum is a group of plant species of the family Crassulaceae native to Madagascar. It is a section or subgenus within the genus Kalanchoe, and was formerly placed at the level of genus. This section is notable for vegetatively growing small plantlets on the fringes of the leaves; these eventually drop off and root. These plantlets arise from mitosis of meristematic-type tissue in notches in the leaves.
Hylotelephium telephium, known as orpine, livelong, frog's-stomach, harping Johnny, life-everlasting, live-forever, midsummer-men, Orphan John, witch's moneybags, and garden stonecrop is a succulent perennial plant of the family Crassulaceae native to Eurasia. The flowers are held in dense heads and can be reddish or yellowish-white. A number of cultivars, often with purplish leaves, are grown in gardens as well as hybrids between this species and the related Hylotelephium spectabile (iceplant), especially the popular 'Herbstfreude'. Occasionally garden plants may escape and naturalise as has happened in parts of North America.
Rhodiola is a genus of perennial plants in the family Crassulaceae that resemble Sedum and other members of the family. Like sedums, Rhodiola species are often called stonecrops. Some authors merge Rhodiola into Sedum.
Phedimus spurius, the Caucasian stonecrop or two-row stonecrop, is a species of flowering plant in the family Crassulaceae. It is still widely listed in the literature as Sedum spurium.
Rosularia is a small genus of the family Crassulaceae. It includes about 28-35 species from Europe, the Himalayas, and northern Africa.
Hylotelephium is a genus of flowering plants in the stonecrop family Crassulaceae. It includes about 33 species distributed in Asia, Europe, and North America.
Aizopsis is a genus of the succulent family Crassulaceae, found in east Asia.
Petrosedum is a genus of the succulent family Crassulaceae.
Phedimus is a genus of the succulent family Crassulaceae, with about 18 species, distributed in eastern Europe and Asia. The genus is described with two subgenera, but one of these is also recognized as a separate genus, Aizopsis. Phedimus kamtschaticus is widely grown as an ornamental ground cover and has gained the Royal Horticultural Society's Award of Garden Merit.
Perrierosedum is a genus of succulent plant in the family Crassulaceae containing only one species, Perrierosedum madagascariense. It is a critically endangered species endemic to Madagascar.
Haworthiopsis is a genus of succulent plants in the subfamily Asphodeloideae. The genus was previously included in Haworthia. Species in the genus are typically short perennial plants, with leaves often arranged in a rosette and frequently having raised white markings. The two-lipped flowers are borne on a tall stalk and are small – less than 17 mm (0.7 in) long – and pale in colour. Many species are cultivated as house plants or by succulent enthusiasts.
Sempervivoideae is the largest of three subfamilies in the Saxifragales family Crassulaceae, with about 20–30 genera with succulent leaves. Unlike the two smaller subfamilies, it is distributed in temperate climates. The largest genus in this subfamily is Sedum, with about 470 species.
Afrovivella is a monotypic genus of the succulent plant family Crassulaceae. The sole species is Afrovivella semiensis.
Kalanchoideae is one of three subfamilies in the Saxifragales family Crassulaceae, with four succulent genera.
