| Taiwan plum yew | |
|---|---|
Scientific classification  | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Gymnospermae |
| Division: | Pinophyta |
| Class: | Pinopsida |
| Order: | Cupressales |
| Family: | Taxaceae |
| Genus: | Cephalotaxus |
| Species: | |
| Variety: | C. h. var. wilsoniana |
| Trinomial name | |
| Cephalotaxus harringtonii var. wilsoniana (Hayata) Kitam. | |
| Synonyms [ citation needed ] | |
| |
Cephalotaxus harringtonii var. wilsoniana, commonly known as Taiwan plum yew and Wilson plum yew, is an endangered variety of conifer endemic to Taiwan. [1]
The genus name Cephalotaxus comes from the Greek "kephale", meaning head. The suffix taxus refers to the yew plant. Together these names mean "head yew" which is in reference to the flower structures that appear as tight clusters or heads. The needle like leaves resemble a yew thus the name "head yew". [2] The common name plum yew comes from the cones that resemble a plum in both shape and color. [2]
The Taiwan plum yew was originally considered as a variety of Cephalotaxus sinensis due to similar morphology, however DNA evidence suggests that it is more closely related to its Japanese cousin Cephalotaxus harringtonii. [3] It has also been considered as a separate species. Currently, some authorities do not recognize the Taiwan plum yew as a distinct taxon, and consider it to be a synonym of the parent species. [4]
The foliage is similar to true yews. The leaves are arranged in a "v"-shaped linear row on the stem, and on the base of the stem the leaves are arranged in a spiral. [5] The foliage is a rich green when mature. New shoots are a bright green and darken after three to four years. [6]
The Taiwan plum yew is endemic to the island of Taiwan where it grows in humus rich soil or gravel cliffs. They grow as small trees or bushes in the understories of wet subtropical forests or warm-temperate forests. This variety grows in mixed deciduous and evergreen forests and prefers locations with light to full shade. It is found at elevations of 1,500 to 2,000 meters. [3] [2] [7]
This variety is distinguished by the reproductive strobili. The seed of the plum yew is approximately the size of an olive or small plum and is larger than those of a true yew. The seed is enclosed by a hard, thin shell and a fleshy outer coat. The outer coat changes colors as the seed ripens from a blue-green to a rich red and finally to a purple-brown. Once it turns purple-brown the fleshy outside degrades causing it to detach from the seed. [2]
This Taiwan plum yew is dioecious with the male and female strobili on different plants. Male strobili are created in clusters of anthers attached to a flat head. The anthers are about 0.25 inches in diameter and are arranged in the axils of the leaves. Female strobili develop in ovules. Often found in pairs of six to twelve, these ovules are attached to an oval, mauve colored cone which will start to expand at 0.5 inches up to 1.25 inches when matured. There is one mature seed per cone, and three to five female cones are grown on stalks near or at the end of the current or last year's branch. Female cones are wind-pollinated. [2]
Seeds have a long maturation time, and the pollen cones usually take nine to eleven months from initiation to dispersal. Female cones take twenty-one months to mature from initiation. [2]
Cultivation of the variety Cephaltaxus harringtonia var. wilsoniana is limited to a only a few nurseries. [2]
The variety is considered endangered due to habitat loss caused by logging, population fragmentation, and ground clearance to make room for plantations of Cryptomeria species. It is concentrated in the northern part of Taiwan where conservation is widespread. [3]
The wood is used for fire and medicinal purposes. The seeds from female cones are also collected for oil. It is increasingly used in medicine due to the anticancer compounds found in the vegetative tissues and seeds. Experiments have been conducted with ester alkaloids, but no therapeutic applications have been announced. [2]
A sporangium ; pl.: sporangia) is an enclosure in which spores are formed. It can be composed of a single cell or can be multicellular. Virtually all plants, fungi, and many other groups form sporangia at some point in their life cycle. Sporangia can produce spores by mitosis, but in land plants and many fungi, sporangia produce genetically distinct haploid spores by meiosis.
Conifers are a group of cone-bearing seed plants, a subset of gymnosperms. Scientifically, they make up the division Pinophyta, also known as Coniferophyta or Coniferae. The division contains a single extant class, Pinopsida. All extant conifers are perennial woody plants with secondary growth. The great majority are trees, though a few are shrubs. Examples include cedars, Douglas-firs, cypresses, firs, junipers, kauri, larches, pines, hemlocks, redwoods, spruces, and yews. As of 2002, Pinophyta contained seven families, 60 to 65 genera, and more than 600 living species.
Podocarpus totara, also known as the tōtara, is a species of podocarp tree endemic to New Zealand. It grows throughout the North Island, South Island and rarely on Stewart Island / Rakiura in lowland, montane and lower subalpine forest at elevations of up to 600 m.
Taxaceae, commonly called the yew family, is a coniferous family which includes six extant and two extinct genera, and about 30 species of plants, or in older interpretations three genera and 7 to 12 species.
A conifer cone or, in formal botanical usage, a strobilus, pl.: strobili, is a seed-bearing organ on gymnosperm plants, especially in conifers and cycads. They are also called, according to the relevant genus, cypress cone, fir cone, pine cone, spruce cone, etc. They are usually woody, and variously conic, cylindrical, ovoid, to globular, and have scales and bracts arranged around a central axis, but can be fleshy and berry-like. The cone of Pinophyta contains the reproductive structures. The woody cone is the female cone, which produces seeds. The male cone, which produces pollen, is usually ephemeral and much less conspicuous even at full maturity. The name "cone" derives from Greek konos, which also gave name to the geometric cone. The individual plates of a cone are known as scales. In conifers where the cone develops over more than one year, the first year's growth of a seed scale on the cone, showing up as a protuberance at the end of the two-year-old scale, is called an umbo, while the second year's growth is called the apophysis.
Nageia is a genus of conifers belonging to the podocarp family Podocarpaceae. Nageia includes evergreen shrubs and trees, from one to 54 meters in height. A 2009 treatment of the genus recognized five species. Some authors consider Nageia formosensis to be a separate species from Nageia nagi, thus recognizing six species. The podocarp genera have been reshuffled by various botanists. Most recently, several species formerly classed as Nageia were moved to the new genus Retrophyllum, while Nageia falcata and Nageia mannii were moved to the new genus Afrocarpus.
Afrocarpus is a genus of conifer of the family Podocarpaceae. Two to six species are recognized. They are evergreen trees native to Africa. Afrocarpus was designated a genus in 1989, when several species formerly classified in Podocarpus and Nageia were reclassified.
Podocarpus macrophyllus is a conifer in the genus Podocarpus, family Podocarpaceae. It is the northernmost species of the genus, native to southern Japan and southern and eastern China. Common names in English include yew plum pine, Buddhist pine, fern pine and Japanese yew. Kusamaki (クサマキ) and inumaki (犬槇) are Japanese names for this tree. In China, it is known as luóhàn sōng (羅漢松), which literally means "arhat pine".
Taxus brevifolia, the Pacific yew or western yew, is a species of tree in the yew family Taxaceae native to the Pacific Northwest of North America. It is a small evergreen conifer, thriving in moisture and otherwise tending to take the form of a shrub.
Juniperus thurifera is a species of juniper native to the mountains of the western Mediterranean region, from southern France across eastern and central Spain to Morocco and locally in northern Algeria.
Cephalotaxus, commonly called plum yew or cowtail pine, is a genus of conifers comprising 11 species, either considered the only member of the family Cephalotaxaceae, or in the Taxaceae when that family is considered in a broad sense. The genus is endemic to eastern Asia, though fossil evidence shows it had a wider Northern Hemisphere distribution in the past. The species are evergreen shrubs and small trees reaching 1.0–10 metres (3–33 ft) tall.
Amentotaxus is a genus of conifers (catkin-yews) comprising five species, treated in either the Cephalotaxaceae, or in the Taxaceae when that family is considered in a broad sense. The genus is endemic to subtropical Southeast Asia, from Taiwan west across southern China to Assam in the eastern Himalaya, and south to Vietnam. The species are evergreen shrubs and small trees reaching 2–15 m tall.
Phyllocladus aspleniifolius, commonly known as the celerytop pine, is an endemic gymnosperm of Tasmania, Australia. It is widespread and common in Tasmania, with the most abundance in the western highlands. Its ‘leaves’ appear similar to those of a celery plant, hence the common name.
A strobilus is a structure present on many land plant species consisting of sporangia-bearing structures densely aggregated along a stem. Strobili are often called cones, but some botanists restrict the use of the term cone to the woody seed strobili of conifers. Strobili are characterized by a central axis surrounded by spirally arranged or decussate structures that may be modified leaves or modified stems.
Cephalotaxus hainanensis is a species of conifer known by the common name Hainan plum-yew. It is native to southern China, southeastern Tibet, and Myanmar, Thailand, and Vietnam in northern Indochina.
Calocedrus formosana is a conifer endemic to Taiwan.
Tsuga chinensis, commonly referred to as the Taiwan or Chinese hemlock, is a coniferous tree species native to China, Taiwan, and Vietnam. The tree is quite variable and has many recognised varieties, though some are also maintained to be separate species by certain authorities. The tree was recently discovered in the mountains of northern Vietnam, making that the southernmost extension of its range.
Cephalotaxus harringtonii, commonly known as Korean plum yew, Japanese plum-yew, Harrington's cephalotaxus, or cowtail pine, is a species of coniferous shrub or small tree in the family Taxaceae. It is native to Japan, but is occasionally utilised in western gardens and several cultivars exist for these purposes. Japanese plum yew has been in cultivation in Europe since 1829, and many modern horticulturists are familiar with this Japanese species, named in honour of Charles Stanhope, 4th Earl of Harrington, one of the first to grow the plant in a European garden, at Elvaston.
Cephalotaxus wilsoniana is a species of coniferous tree in the yew family, Taxaceae. Its common names include Taiwan plum yew, Taiwan cow's-tail pine, and Wilson plum yew. It is endemic to Taiwan, scattered in montane forests at altitudes of 1400-2700 meters. As Cephalotaxus wilsoniana is dioecious, and grows scattered with broad-leaved trees, the fecundity is not strong. In addition, the seed maturity period is very long. As germination and growth are also slow, Cephalotaxus wilsoniana is not commonly found.
Retrophyllum vitiense is a species of conifer in the family Podocarpaceae. It is a large evergreen rainforest emergent tree native to Fiji, Vanuatu, and the Santa Cruz Islands.
