Dioscorea | |
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Dioscorea balcanica | |
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Monocots |
Order: | Dioscoreales |
Family: | Dioscoreaceae |
Genus: | Dioscorea L. |
Sections | |
(Not all are supported by molecular analyses. [1] See tropicos query cited for more. [2] ) Contents | |
Synonyms [3] | |
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Dioscorea is a genus of over 600 species of flowering plants in the family Dioscoreaceae, native throughout the tropical and warm temperate regions of the world. The vast majority of the species are tropical, with only a few species extending into temperate climates. [3] [4] [5] [6] It was named by the monk Charles Plumier after the ancient Greek physician and botanist Dioscorides.
This section may contain material not related to the topic of the article and should be moved to Chinese Yam instead.(December 2023) |
Wild Yam (Dioscorea) is a vine that is invasive, deciduous, and herbaceous. [7] [ not specific enough to verify ] This species is native to Asia, though, in the U.S., it is commonly found in Florida. They can grow over 18 metres (60 feet) in length. [8] [ irrelevant citation ] Wild yams are an important crop, as they have been used to prevent menstrual cramps, stomach cramps, and general pain for centuries. During the 1950s scientists found that the roots of wild yams contained diosgenin which is a plant-based estrogen; diosgenin is hypothesized to aid in chemical defense against herbivores. This was used to create the first birth control pills during the 60s. [9] In addition, some Dioscorea species are rich in nutrients and antioxidants. This is beneficial in rural areas where the plant is native because it enriches the diets of individuals who live in the area. [10] These plants grow best near canopy gaps in woodlands and rainforests. Dioscorea uses vining behavior which is useful in tropical habitats because Dioscorea grow under canopies and need to latch onto different surfaces in order to grow upwards and acquire resources. [11]
Several species, known as yams, are important agricultural crops in tropical regions, grown for their large tubers. Many of these are toxic when fresh, but can be detoxified and eaten, and are particularly important in parts of Africa, Asia, and Oceania.
One class of toxins found in many species is steroidal saponins, which can be converted through a series of chemical reactions into steroid hormones for use in medicine and as contraceptives.
The 1889 book "The Useful Native Plants of Australia" records that Dioscorea hastifolia is "One of the hardiest of the yams. The tubers are largely consumed by the local aborigines for food. (Mueller)." [12]
Although the mechanism of Dioscorea vine behavior is unknown, it is likely that Dioscorea acts similarly to vines in terms of growth and movement behavior. Vines have a touch-sensitive component that allows them to locate and latch onto a supporting base. They use nearby plants, rocks, trees, and structures for physical support. Their touch receptors allow them to reach out and sense objects. Vines seek out these surfaces by sending out shoots to assess the area. This behavior is dependent on the species, but these shoots typically move in a clockwise or counterclockwise direction, induced by circadian rhythms. [13] [14] When the vine makes contact with an object, the tendril shoot will coil around the object; this is a reaction called thigmotropism. [15] This tendril can control the amount of tension and squeeze the object to stay attached to it and prevent falling. Leaf growth is typically postponed until the relative stem has secured support. When leaf growth is delayed, shoot growth is hastened. Some vines produce an adhesive on their stems that contain calcium to better latch onto structures. A gradient is produced and the calcium exits cells to spread over stems. Furthermore, Dioscorea is a twiner, this means that the plant undergoes circumnutation which is a helical movement that allows stems to wrap around objects. In order for this mechanism to take place, endodermal cells, plasmodesmata, the plasma membrane, epidermal cells, calcium, potassium, chloride, and proton pumps are required. [16] The SCR gene is also crucial for twining to occur. [17]
In 2009, an experiment was conducted to address the mechanism of force generation in the twining plant, Dioscoreabulbifera. To do this, the authors used a mechanical pole that measured the squeezing force of the twining vine. Plants were grown in a greenhouse setting, and once the shoots of the plants started "circumnutating," a pole was introduced to allow for twining around the object. Authors found that the amount of force being applied to the pole when the vine is twining is due to the stretching of the stipule. The forces of the bending and twisting motion of D. bulbifera did not generate a measurable force. In addition, this experiment indicates that stipules [18] are not the only driving force for tension in vines and that they contribute to increased squeezing force later in development. [19]
Overall, Dioscorea has a vining mechanism that allows it to obtain nutrients while living under a canopy; it has evolved to do this by seeking out surfaces to climb and latch onto. Vines, like Dioscorea, have touch-sensitive components that allow them to specialize in this behavior.
The Alangan Tribe of Mangyan in the Island of Mindoro in the Philippines, locally known as Karot/Nami; Uses this type of tuber as an alternative of rice. Mangyan people typically soak it for 3 days, wash it in the running streams, dried for 2 days, and soak for 2 hours before cooking like a typical rice.
This section may require cleanup to meet Wikipedia's quality standards. The specific problem is: May be more useful to arrange by section, however unreliable molecularly they can be.(October 2021) |
The genus includes the following species and subspecies:[ citation needed ]
The closely related genus Tamus is included in Dioscorea by some sources, [22] but is maintained as distinct by others. [23] For Dioscorea communis (L.) Caddick & Wilkin, see Tamus communis .
Gentiana is a genus of flowering plants belonging to the gentian family (Gentianaceae), the tribe Gentianeae, and the monophyletic subtribe Gentianinae. With over 300 species, it is considered a large genus. Gentians are notable for their mostly large trumpet-shaped flowers, which are often of an intense blue hue.
Smilax is a genus of about 300–350 species, found in the tropics and subtropics worldwide. They are climbing flowering plants, many of which are woody and/or thorny, in the monocotyledon family Smilacaceae, native throughout the tropical and subtropical regions of the world. Common names include catbriers, greenbriers, prickly-ivys and smilaxes. Sarsaparilla is a name used specifically for the Neotropical S. ornata as well as a catch-all term in particular for American species. Occasionally, the non-woody species such as the smooth herbaceous greenbrier are separated as genus Nemexia; they are commonly known by the rather ambiguous name carrion flowers.
The flowering plant genus Ipheion belongs to Allioideae, a subfamily of the family Amaryllidaceae. It includes three species native to southern Brazil, northeastern Argentina, and Uruguay.
The Celastraceae are a family of 98 genera and 1,350 species of herbs, vines, shrubs and small trees, belonging to the order Celastrales. The great majority of the genera are tropical, with only Celastrus, Euonymus and Maytenus widespread in temperate climates, and Parnassia (bog-stars) found in alpine and arctic climates.
Cynanchum is a genus of about 300 species including some swallowworts, belonging to the family Apocynaceae. The taxon name comes from Greek kynos and anchein, hence the common name for several species is dog-strangling vine. Most species are non-succulent climbers or twiners. There is some evidence of toxicity.
Calceolaria, also called lady's purse, slipper flower and pocketbook flower, or slipperwort, is a genus of plants in the family Calceolariaceae, sometimes classified in Scrophulariaceae by some authors. This genus consists of about 388 species of shrubs, lianas and herbs, and the geographical range extends from Patagonia to central Mexico, with its distribution centre in Andean region. Calceolaria species have usually yellow or orange flowers, which can have red or purple spots. The Calceolaria Herbeohybrida group, also called C. herbeohybrida Voss, is a group of ornamental hybrids known only in cultivation, called florists' slipperwort.
Nassauvia is a genus of flowering plants in the tribe Nassauvieae within the family Asteraceae. It is native to Argentina, Bolivia, Chile and the Falkland Islands.
Dioscorea transversa, the pencil yam, is a vine of eastern and northern Australia.
Dioscorea japonica, known as East Asian mountain yam, yamaimo, or Japanese mountain yam, is a type of yam (Dioscorea) native to Japan, Korea, China, Taiwan, and Assam.
Tristagma is a genus of South American plants in the onion subfamily with the Amaryllis family. It includes 17 species native to Peru, Argentina, and Chile in South America.
Rajania is a genus of plants in the Dioscoreaceae. It is native to the West Indies, with 14 of the 17 known species found in Cuba.