Poliothyrsis | |
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Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Eudicots |
Clade: | Rosids |
Order: | Malpighiales |
Family: | Salicaceae |
Subfamily: | Salicoideae |
Tribe: | Saliceae |
Genus: | Poliothyrsis Oliv. |
Species: | P. sinensis |
Binomial name | |
Poliothyrsis sinensis Hook.f. | |
Poliothyrsis is a monotypic genus of flowering plants belonging to the willow family Salicaceae (although placed formerly in the now defunct family Flacourtiaceae (within which it is usually to be found listed in older works of reference)). [1] [2] The single arborescent species is Poliothyrsis sinensis, [1] Chinese common name: 山拐枣 shān guǎi zǎo [3] English common name: Chinese pearl-bloom tree [4]
A small deciduous tree 7-15m in height and circa 6m in spread, with pubescent young shoots. Leaves ovate, long-pointed 11.5 to 15 cm in length , very downy beneath when young, petioles reddish, 19-38mm long. Flowers small, circa 8.5mm across, at first white but becoming yellowish, in terminal, loose panicles 15 cm or more in length, both male and female in the same inflorescence, borne in June–July. Fruit a dry capsule, ovoid, tomentose, individual valves acutely fusiform (= spindle-shaped), 2–3 cm, ca. 1 cm in diam. Seeds wind-dispersed, compressed-flat, each surrounded and enclosed by a ± elliptic or oblong wing 5–10 mm, seed proper small, less than 1/2 as long as wing. Fruits borne July–September. [3] [5]
The ripe seed capsules of P. sinensis, which initially resemble in size and shape those of the lilac, develop to display a remarkable 'double dehiscence'. When ripe, they assume a greenish-gray colour, after which their outer layer sloughs off to reveal inner walls of a buff colour. Once the outer walls have fallen away the remaining inner walls dehisce both by three valves from the tip, and, more surprisingly, by three from the base, creating what is effectively a tube, toothed above and below, through which the wind can blow out the small winged seeds. This uncommon ‘double dehiscence’, by both apex and base, is to be found also in the seed capsules of the unrelated Franklinia alatamaha (Franklinia being a monotypic genus belonging to the tea plant family Theaceae). Long after the seeds of Poliothyrsis have been dispersed by the wind, the empty capsules, with their gaping teeth at either end, remain on the plant well into the winter months, lending decorative interest with their unusual form. [6]
Poliothyrsis bears a marked resemblance (particularly in its foliage) to Idesia , another monotypic genus belonging, (as also do the familiar Poplars and Willows) to tribe Saliceae of the family Salicaceae. As the RHS points out, Poliothyrsis differs from Idesia in the following three points:
The genus name Poliothyrsis is of Greek derivation, being composed of the elements πολιός (polios), meaning "light grey", "grizzled" or "silvery" (employed usually in reference to human hair) [7] and θύρσος ( thyrsos ) meaning "stalk" or "wand" (or, in a botanical sense, panicle), [8] juxtaposed to give the apt description "bearing silvery (or bright) flower clusters". The Latin specific epithet sinensis, used in the name of the single species, means "native to China". [9] [5]
山拐枣 (shān guǎi zǎo), the Chinese vernacular name for P. sinensis, translates as "mountain raisin tree", where the character 山 (shān) signifies "mountain" [10] and the two-character compound 拐 枣 (guǎi zǎo)* designates the fruit tree Hovenia acerba (family Rhamnaceae). [11] The likeness between Poliothyrsis and Hovenia referenced in this common name is one not of fruit but of foliage (unlike Hovenia acerba, Poliothyrsis does not produce edible fruit): the leaves of Poliothyrsis sinensis bear a marked resemblance to those of Hovenia acerba. The qualification "mountain" references the fact that, while the ranges of P. sinensis and H. acerba overlap in central China, [12] P. sinensis (as noted below) shows a preference for the mountainous areas of this region. [3] Hovenia acerba readily presents itself as a tree species inviting comparison with others present in Southern China, since it has not only long been cultivated for its edible fruit (used also in the preparation of traditional wines), but has also been widely used as a street tree in southern Chinese cities. [13]
Its native range is North-Central, South-Central, and Southeast China, where temperate climates of various subtypes prevail (Köppen climate classification group C) [1] [3]
P. sinensis occurs in evergreen and deciduous broad-leaved mixed forests and deciduous broad-leaved forests on mountain slopes or at the foot of mountains, growing at altitudes of 400–1500 m. [3]
Although frequently used in landscaping projects in its native China, [15] the plant is not yet common in cultivation in Europe and the U.S.A., despite its merits - which are acknowledged as considerable by Jonathan Damery of the Arnold arboretum, who describes the plant in glowing terms as “ show-stopping”, a potential “garden celebrity” and having “elegance”, “class” and a praiseworthy “lack of gaudiness” in its restrained beauty. [16] The tree is grown for its glossy, dark, emerald green leaves (which later provide warm yellow Autumn colour) and fragrant, papery, greenish-white flowers which gradually become yellow as they mature. [17]
P. sinensis is fully hardy in the U.K. and is best grown in a fertile, well-drained soil in full sun or partial shade, with shelter from cold, drying winds. It requires minimal pruning, such pruning consisting in the removal of wayward or crossing shoots in late Winter or early Spring, with the aim of maintaining a robust and shapely framework. The plant is best propagated by the sowing of seed in containers in an open frame in Autumn, but may also be increased vegetatively by the taking of greenwood cuttings in Summer. In regard to pests and diseases, the plant is generally trouble-free. [17]
The tree is hardy to USDA Zone 6 (circa −5 °F (−20.6 °C)). [16]
Profuse in its production of fragrant flowers, the tree is valued as a nectar plant in its native China. The wood is fine-grained and of good quality and is used in China in the making of furniture and the carving of various utensils. [15] [18]
In the year 1969 pioneering French chemotaxonomist Victor Plouvier published a paper in which he recorded his isolation of a new crystalline glycoside from P. sinensis, which he had duly named poliothyrsoside. [19] However, only a year later, in 1970, H. Thieme published another scientific paper in which he demonstrated that poliothyrsoside was in fact chemically identical to the glycoside nigracin, [20] first isolated and characterised from the bark and leaves of Populus nigra , the black poplar, by himself and his colleague R. Benecke in 1967. [21] [22] A Japanese investigation of 2014 noted the presence of three compounds of interest in the plant: 3-(6-O-Benzoyl-β-D-glucopyranosyloxy)-5-hydroxycinnamic acid methyl ester, Flacourtoside A and Homaloside. [23]
Decumaria, the woodvamps, is a genus of two species of flowering plants in the family Hydrangeaceae, one native to the southeastern United States, and the other native to central China.
Jujube, sometimes jujuba, known by the scientific name Ziziphus jujuba and also called red date, Chinese date, and Chinese jujube, is a species in the genus Ziziphus in the buckthorn family Rhamnaceae. It is often confused with the closely related Indian Jujube, Z. mauritiana. The Chinese jujube enjoys a diverse range of climates from temperate to tropical, whereas the Indian jujube is restricted to warmer subtropical and tropical climates.
The loquat, called biwa in Japan, is a large evergreen shrub or tree grown commercially for its orange fruit and for its leaves, which are used to make herbal tea. It is also cultivated as an ornamental plant.
Theaceae, the tea family, is a family of flowering plants comprising shrubs and trees, including the economically important tea plant, and the ornamental camellias. It can be described as having from seven to 40 genera, depending on the source and the method of circumscription used. The family Ternstroemiaceae has been included within Theaceae; however, the APG III system of 2009 places it instead in Pentaphylacaceae. Most but not all species are native to China and East Asia.
Koelreuteria, also known as chinese lantern tree, is a genus of three species of flowering plants in the family Sapindaceae, native to southern and eastern Asia.
Aesculus hippocastanum, the horse chestnut, is a species of flowering plant in the maple, soapberry and lychee family Sapindaceae. It is a large, deciduous, synoecious (hermaphroditic-flowered) tree. It is also called horse-chestnut, European horsechestnut, buckeye, and conker tree. It is not to be confused with the Spanish chestnut, Castanea sativa, which is a tree in another family, Fagaceae.
Wisteria sinensis, commonly known as the Chinese wisteria, is a species of flowering plant in the pea family, native to China, in the provinces of Guangxi, Guizhou, Hebei, Henan, Hubei, Shaanxi, and Yunnan. Growing 20–30 m (66–98 ft) tall, it is a deciduous vine. It is widely cultivated in temperate regions for its twisting stems and masses of scented flowers in hanging racemes, in spring.
Staphylea, called bladdernuts, is a small genus of 10 or 11 species of flowering plants in the family Staphyleaceae, native to temperate regions of the Northern Hemisphere. The highest species diversity is in China, where four species occur.
Koelreuteria elegans, more commonly known as flamegold rain tree, is a deciduous tree 15–17 metres tall. There are currently two subspecies under this taxa, i.e., K. elegansssp.elegans, which is endemic to Fiji, and K. elegansssp. formosana, which is endemic to Taiwan. The subspecies formosana, commonly known as Taiwanese golden rain tree, is widely grown throughout the tropics and sub-tropical parts of the world as a street tree.
Catalpa bignonioides is a short-lived species of Catalpa that is native to the southeastern United States in Alabama, Florida, Georgia, Louisiana, and Mississippi. Common names include southern catalpa, cigartree, and Indian-bean-tree. It is commonly used as a garden and street tree.
Calodendrum capense, the Cape chestnut, is an African tree which was first studied at The Cape in South Africa and cultivated widely for its prolific flower display. The tree obtained the common name of "Cape chestnut" because explorer William Burchell saw a resemblance to the horse chestnut in terms of flowers and fruit, though the two are not closely related.
Hovenia dulcis, the Japanese raisin tree or oriental raisin tree, is a hardy tree found in Asia, from Eastern China and Korea to the Himalayas, growing preferably in a sunny position on moist sandy or loamy soils. The tree known for its health benefits when consumed in tea, introduced as an ornamental tree to several countries, also bears edible fruit. It is considered to be one of the most pervasive invaders in Brazilian subtropical forests.
Aphanamixis polystachya, the pithraj tree, is a species of tree in the family Meliaceae. It is native to India, Pakistan, Nepal, Bhutan, Bangladesh, Myanmar and Sri Lanka. It is a widely used as a medicinal plant in Ayurveda.
Toona sinensis, commonly called Chinese mahogany, Chinese cedar, Chinese toon, beef and onion plant, or red toon is a species of Toona native to eastern and southeastern Asia, ranging from northern Korean peninsula through most of eastern, central, and southwestern China, in Nepal, northeastern India, Burma (Myanmar), Thailand, and even present in Malaysia and western Indonesia.
Gleditsia sinensis, known as zào jiá (皂荚) or Chinese honey locust and black locust in English, is a species of flowering plant native to Asia.
Didymocheton rufus is a rainforest tree in the family Meliaceae, found in eastern Australia. It occurs on a variety of different soils and rainforest types. From as far south as Bulahdelah, New South Wales to the McIlwraith Range in far north eastern Australia. The specific epithet rufus refers to the rusty red of the leaf, fruit and flower hairs of this species.
Populus ciliata, the Himalayan poplar, is a large deciduous tree with tall clean straight trunk and wide rounded crown. The bark of the young trees is smooth greenish-grey and the bark of the old trees is dark brown with vertical cracks. Leaves are broadly ovate with serrulate-crenate and hairy margins. Flowers are drooping raceme catkins appear before or with leaves. Populus ciliata flowers are dioecious, individual flowers are either male or female. Perianth of male flowers is bell-shaped and female flowers are bluntly toothed. Their capsule encloses an average of 100–150 seeds, which are covered by long silky hair.
Aesculus chinensis, the Chinese horse chestnut or Chinese buckeye, is a deciduous temperate tree species in the genus Aesculus found across China. It was first successfully introduced to Britain in 1912 by plant collector William Purdom, who collected six young plants from the grounds of a temple in the western hills of Beijing, and brought them back to Veitch's Nursery in Coombe Hill near London. Purdom's correspondence regarding this event are held in the archives of the Arnold Arboretum. One plant was sent to the Royal Botanic Gardens Kew and two to the Arnold Arboretum in Boston. The original tree at Kew no longer exists but a young tree grafted from the original now grows in the Rhododendron Dell.
Atropanthe is a monotypic genus of flowering plants belonging to tribe Hyoscyameae of subfamily Solanoideae of the family Solanaceae.
Hovenia acerba is a species of flowering plant in the raisin tree genus Hovenia, native to temperate areas of Nepal, the eastern Himalayas, Assam, Myanmar, northern Thailand, Tibet, and central and southern China. A tree reaching 25 m (82 ft), it is found at elevations up to 2,100 m (6,900 ft), in wooded and open areas, forest edges, and slopes, and it is frequently cultivated locally.