![1 Orostachys spinosa wisley](https://upload.wikimedia.org/wikipedia/commons/7/72/1_Orostachys_spinosa_wisley.jpg)
''Orostachys'' is a genus of the succulent family
Crassulaceae
The Crassulaceae (from Latin ''crassus'', thick), 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 Crass ...
(stonecrop family) that contains about 15 species. It is a biennial herb growing in
China,
Japan,
Kazakhstan
Kazakhstan, officially the Republic of Kazakhstan, is a transcontinental country located mainly in Central Asia and partly in Eastern Europe. It borders Russia to the north and west, China to the east, Kyrgyzstan to the southeast, Uzbeki ...
,
Korea
Korea ( ko, 한국, or , ) is a peninsular region in East Asia. Since 1945, it has been divided at or near the 38th parallel, with North Korea (Democratic People's Republic of Korea) comprising its northern half and South Korea (Republic o ...
,
Mongolia
Mongolia; Mongolian script: , , ; lit. "Mongol Nation" or "State of Mongolia" () is a landlocked country in East Asia, bordered by Russia to the north and China to the south. It covers an area of , with a population of just 3.3 million, ...
,
Russia
Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-eig ...
. Eight species occur in
China.
Description
''Orostachys'' are the most
morphologically distinct member of subfamily
Sempervivoideae
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 ...
. Orostachys species are mostly
biennial
Biennial means (an event) lasting for two years or occurring every two years. The related term biennium is used in reference to a period of two years.
In particular, it can refer to:
* Biennial plant, a plant which blooms in its second year and th ...
herbaceous plants that are more or less succulent.
Leaves are linear to ovate, often with dull purple dots. The arrangement is
alternate
Alternative or alternate may refer to:
Arts, entertainment and media
* Alternative (''Kamen Rider''), a character in the Japanese TV series ''Kamen Rider Ryuki''
* ''The Alternative'' (film), a 1978 Australian television film
* ''The Alternative ...
, forming crowded
cauline
A leaf ( : leaves) is any of the principal appendages of a vascular plant stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, ste ...
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
root
In vascular plants, the roots are the organs of a plant that are modified to provide anchorage for the plant and take in water and nutrients into the plant body, which allows plants to grow taller and faster. They are most often below the su ...
s 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
inflorescence
An inflorescence is a group or cluster of flowers arranged on a Plant stem, stem that is composed of a main branch or a complicated arrangement of branches. Morphology (biology), Morphologically, it is the modified part of the shoot of sperma ...
s, usually branched and composed of individual
spicate
This glossary of botanical terms is a list of definitions of terms and concepts relevant to botany and plants in general. Terms of plant morphology are included here as well as at the more specific Glossary of plant morphology and Glossary o ...
inflorescences, are relatively large and narrowly pyramidal to cylindrical, containing many flowers and foliage-like
bracts. The
flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechani ...
s, which are at most very short-stemmed, are
hermaphroditic
In reproductive biology, a hermaphrodite () is an organism that has both kinds of reproductive organs and can produce both gametes associated with male and female sexes.
Many taxonomic groups of animals (mostly invertebrates) do not have s ...
and pentamerous. The free
sepal
A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 The term ''sepalum'' was coine ...
s 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
ovule
In seed plants, the ovule is the structure that gives rise to and contains the female reproductive cells. It consists of three parts: the '' integument'', forming its outer layer, the ''nucellus'' (or remnant of the megasporangium), and the ...
s. The
styles are narrow.
The many-seeded
follicles possess a beak-like end. The seeds are small.
Taxonomy
Within family
Crassulaceae
The Crassulaceae (from Latin ''crassus'', thick), 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 Crass ...
, ''Orostachys'' is placed in tribe Telephieae of subfamily
Sempervivoideae
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 ...
. The genus has. at times, included ''
Meterostachys''.
Molecular phylogenetics
Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...
shows that the genus is not
monophyletic, but
polyphyletic
A polyphyletic group is an assemblage of organisms or other evolving elements that is of mixed evolutionary origin. The term is often applied to groups that share similar features known as homoplasies, which are explained as a result of conver ...
relative to
paraphyletic ''
Hylotelephium''. Its
circumscription
Circumscription may refer to:
*Circumscribed circle
* Circumscription (logic)
*Circumscription (taxonomy)
*Circumscription theory, a theory about the origins of the political state in the history of human evolution proposed by the American anthrop ...
, therefore, is unstable and subject to revision.
Subdivision
The genus ''Orostachys'' has been divided into series (or sections), including:
* ''Orostachys'' series ''Appendiculatae''
* ''Orostachys'' series ''Eappendiculatae''
Other authors have created two different sections:
* ''Orostachys'' section ''Orostachys''
* ''Orostachys'' section ''Schoenlandia''
Some species were transferred from ''Sinocrassula'' into ''Orostachys'', as section ''Schoenlandia'', also treated as a subgenus or section, or a separate genus ''
Kungia'', e.g. ''O. schoenlandii'' (''Kungia schoenlandii''). ''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:
* ''Orostachys'' subsection ''Orostachys''
* ''Orostachys'' subsection ''Appendiculatae''
On the basis of molecular data, it has been proposed that ''Orostachys'' subsection ''Appendiculatae'' be considered a separate genus.
Species
The genus includes about 12–17 accepted species, including:
* ''
Orostachys aggregata''
(Makino) H. Hara
* ''
Orostachys boehmeri''
V.N. Boriss. – also called ''O. furusei'', endemic plant from Japan
*''
Orostachys cartilaginea''
(H. Lév.) A. Berger
* ''
Orostachys chanetii ''
A. Berger
* ''
Orostachys fimbriata''
(Turcz.) A.Berger
* ''
Orostachys genkaiensis''
Ohwi
* ''
Orostachys iwarenge ''
Hara – Chinese Dunce Cap
* ''
Orostachys malacophylla''
(Pall.) Fisch. – type species
* ''
Orostachys minuta''
(Kom.) A. Berger
* ''
Orostachys paradoxa''
(Khokhr. & Vorosch.) Czerep.
* ''
Orostachys sikokiana''
(Makino) Ohwi
* ''
Orostachys spinosa''
(L.) Sweet
* ''
Orostachys thyrsiflora''
Fisch.
References
Bibliography
* '
full text at'
ResearchGate)
*
*
*
*
* , in
Flora of China online vol. 8
{{Taxonbar, from=Q141475
Crassulaceae
Crassulaceae genera