Crinum thaianum  

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Crinum thaianum:

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Common name

Onion plant; Water onion

Distribution

South Thailand

In Thailand the bulb is used in a cream used to soften the skin.

Description

Long, up to 60 inches (150 cm) (or longer), tough, ribbonlike bright green leaves grow from a bulb that looks much like an onion. White 'lily-like; flowers may form on a long stalk.

There are a number of varieties and forms available. A dwarf plant sold under this species name as Dwarf Onion Plant has yet to be determined.

Cultivation

It requires water temperatures of 72-86 degrees F (22-30 degrees C) and is popular with aquarists because it is easy to keep, tolerant of temperature swings and lighting variations, and because its leaves are tough enough to withstand the attention of herbivorous fish. Propagation is from daughter bulbs. It likes a rich substrate and additional CO2 encourages growth with space to spread and grow. It does well in a warm outside pond

References

Licensehttp://creativecommons.org/licenses/by-sa/3.0/
Rights holder/AuthorWikipedia
Sourcehttp://en.wikipedia.org/w/index.php?title=Crinum_thaianum&oldid=428632488

Crinum thaianum J. Schul., 1971

Materials

Type status: Other material. Occurrence: recordedBy: Y. Ito ; Location: country: Thailand ; locality: Phang Nga Province; Klong Tam Nung ; verbatimLatitude: 8° 27' 22" N; verbatimLongitude: 98° 31' 8" E; Record Level: collectionID: C. Niyomdham 1256; institutionCode: AAU

Type status: Other material. Occurrence: recordedBy: Y. Ito ; Location: country: Thailand ; locality: Phang Nga Province; Ban Nang Yon, 30 miles N of Takua Pa, on the way to Ranong ; verbatimLatitude: 9° 12' 20" N; verbatimLongitude: 98° 25' 28" E; Event: eventDate: Apr. 18, 1970 ; Record Level: collectionID: J. Schulze 357; institutionCode: MO

Type status: Holotype. Occurrence: recordedBy: Y. Ito ; Location: country: Thailand ; locality: Phang Nga Province; Ban Nang Yon, 30 miles N of Takua Pa, on the way to Ranong ; Event: eventDate: Apr. 18, 1970 ; Record Level: collectionID: J. Schulze 1011; institutionCode: US

Distribution

Thailand.

Notes

Lectotype was designated by Lekhak and Yadav (2012).

Fig. 6.

LicensePublic Domain
Rights holder/AuthorNo known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
Sourcehttp://treatment.plazi.org/id/9E954DB20DEF418C0AA8156E10E58327

Crinum thaianum J. Schul., 1971

Materials

Type status: Other material. Occurrence: recordedBy: Y. Ito ; Location: country: Thailand ; locality: Phang Nga Province; Klong Tam Nung ; verbatimLatitude: 8° 27' 22" N; verbatimLongitude: 98° 31' 8" E; Record Level: collectionID: C. Niyomdham 1256; institutionCode: AAU

Type status: Other material. Occurrence: recordedBy: Y. Ito ; Location: country: Thailand ; locality: Phang Nga Province; Ban Nang Yon, 30 miles N of Takua Pa, on the way to Ranong ; verbatimLatitude: 9° 12' 20" N; verbatimLongitude: 98° 25' 28" E; Event: eventDate: Apr. 18, 1970 ; Record Level: collectionID: J. Schulze 357; institutionCode: MO

Type status: Holotype. Occurrence: recordedBy: Y. Ito ; Location: country: Thailand ; locality: Phang Nga Province; Ban Nang Yon, 30 miles N of Takua Pa, on the way to Ranong ; Event: eventDate: Apr. 18, 1970 ; Record Level: collectionID: J. Schulze 1011; institutionCode: US

Distribution

Thailand.

Notes

Lectotype was designated by Lekhak and Yadav (2012).

Fig. 6.

LicensePublic Domain
Rights holder/AuthorNo known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
Sourcehttp://treatment.plazi.org/id/1BD4364F3658A1D4C7C3492E36337DE6

Range Description:

Originally found on the coastal plain of southern Thailand (Leeratiwong and Jornead 2005), but is now confined to isolated patches on a few rivers and streams in Phang Nga and Ranong provinces. Phang Nga province: Khlong Khura Buri/ Nang Yon, Khlong Banglu, Khlong Tam Nung, Khlong Ban Krung, Khlong Bang Pao Moo and Ranong province: Khlong Nakha; Khlong Kapoe, Khlong Bangpong, Khlong Suan Mai, Khlong Ta Pud (http://www.dnp.go.th; IUCN survey). Occurs at low elevations below 150 m.

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Rights holder/AuthorInternational Union for Conservation of Nature and Natural Resources
Sourcehttp://www.iucnredlist.org/apps/redlist/details/201627

Lectotype; Type collection for Crinum thaianum J. Schulze
Catalog Number: US 2830180
Collection: Smithsonian Institution, National Museum of Natural History, Department of Botany
Verification Degree: Original publication and alleged type specimen examined; Original publication and alleged type specimen examined
Preparation: Pressed specimen
Collector(s): J. Schulze
Year Collected: 1970
Locality: B.Nang Yon, 30 mi. north of Takua Pa, on the way to Ranong, southern Thailand, Thailand, Asia-Tropical

  • Lectotype: Lekhak, M. M. & Yadav, S. R. 2012. Kew Bull. 67: 526.; Schulze, J. 1971. Pl. Life. 27: 127.; Type collection: Lekhak, M. M. & Yadav, S. R. 2012. Kew Bull. 67: 526.; Schulze, J. 1971. Pl. Life. 27: 127.
Licensehttp://creativecommons.org/licenses/by/3.0/
Rights holder/AuthorThis image was obtained from the Smithsonian Institution. Unless otherwise noted, this image or its contents may be protected by international copyright laws.
Sourcehttp://collections.mnh.si.edu/search/botany/?irn=10194827

Habitat and Ecology:

Habitat and Ecology

This geophytic plant grows in clear running fresh water, usually in wide and open streams and rivers a few centimetres to two meters in depth depending on the seasonal water level. The soil is usually a sandy loam or mixed gravel. Some streams are shaded, however, in all their sites Crinum receive sunlight at least temporarily (http://www.amaryllidaceae.org). It prefers water temperatures of 22-30C.

Mature bulbs reach 7 cm in diameter and about 15 cm high. The elongated (up to two metres long) float in the direction of the current, or in stiller water are piled in loops. Flowering occurs mainly during the monsoon season (August-October). The inflorescence comprises five to eight flowers. The plant also reproduces vegetatively through the production of bulblets.

The data on the phenology of water onion and water depth in Nakha river, maintained by Mrs. Oy Onkhow (co-leader of a local community based organization Pleun Prai Sri Naka - involved in conservation work in Ranong Province, highlights the following:

January (average water depth of 3-4 m): germination from seeds and leaf production from bulbs starts

February - July (average water depth starts at 1-2 m in March and increases to 5-6 m by July): leaf growth

August (average water depth 6-8 m): flowering is initiated

September (average water depth 8-9 m): peak flowering

October (average water depth 6-9 m): seed formation

November to December (average water depth drops from 6 m down to 4 m): seed is dispersed and laves die back

Preliminary observations on the mid areas of the Nakha River, by a team of IUCN scientists on the 3rd of June 2008 revealed the following: The speed of water flow in mid areas of Nakha River ranged from 0.25-3 m/s. The main population is restricted to a 600 m stretch (width 30 m; depth 1-2.5 m), which has a muddy substrate. The growth was very dense towards the edge of the river. The water flow in this stretch was below 0.3 m/s. The area received ample sunlight. The length of the leaves ranged from 1-3 m, with each bulb having 20-40 leaves. Several fish were observed in this stretch, beneath the thick growth of this plant, which provided an ideal refuge to them. A thin layer of sediment was clearly visible on the leaf surface. Clumps of washed out Water Onion were observed on either side of the river bank, these had been removed by the fast flow of the water.

The Water Onion is a very important aquatic plant that functions as a keystone species in its aquatic habitats. It provides important habitat for native freshwater fish species such as the Soro Brook Carp (Tor soro), which use it as a habitat to lay eggs. Other aquatic species such as water snails and frogs also use it as breeding habitat. Other native fish eat the young leaves of Water Onion.

Systems

  • Freshwater
Licensehttp://creativecommons.org/licenses/by-nc-sa/3.0/
Rights holder/AuthorInternational Union for Conservation of Nature and Natural Resources
Sourcehttp://www.iucnredlist.org/apps/redlist/details/201627

IUCN Red List Assessment:
Red List Category

EN
Endangered

Red List Criteria

B1ab(ii,iii,iv,v)+2ab(ii,iii,iv,v)

Version

3.1

Year Assessed

2011

Assessor/s

Soonthornnawaphat, S., Bambaradeniya, C. & Sukpong, P.

Reviewer/s

Hilton-Taylor, C. & Lutz, M.L.

Contributor/s

Justification

The Water Onion has a very restricted range in southern Thailand, with an extent of occurrence of about 641 km and an area of occupancy of about 48 km. The population is severely fragmented by habitat loss (only 3-5% of the original habitat remains) and there has been rapid population declines in some areas as a result (70% decline in the Nakha River during the period 2003-2008), and there has been local extinction in some streams within its range. The threats to the habitats and the species (exploitation) are all ongoing, hence there is continuing decline in a number of parameters. The species is therefore listed as Endangered and it could well become Critically Endangered in the near future if these trends continue.

IUCN staff in the region are trying to raise awareness about this species and have also been promoting habitat restoration and reintroduction projects in an effort to conserve this species.

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Rights holder/AuthorInternational Union for Conservation of Nature and Natural Resources
Sourcehttp://www.iucnredlist.org/apps/redlist/details/201627

Population:

Population

The population is very fragmented and declining.

Population Trend

Decreasing
Licensehttp://creativecommons.org/licenses/by-nc-sa/3.0/
Rights holder/AuthorInternational Union for Conservation of Nature and Natural Resources
Sourcehttp://www.iucnredlist.org/apps/redlist/details/201627

Threats:

Major Threats

A major threat to the habitat of this species is the dredging of rivers and streams for removal of sediment and rock for construction and land reclamation purposes (this has also increased the speed of water flow in habitats of the Water Onion, where entire subpopulations have been dislodged). Also threatened by diversion of the rivers and streams for agricultural purposes. There is also extensive changes in the ecology of the streams and rivers due to land use changes in the adjoining areas (e.g., clearing of forest for agriculture) and resultant land-based erosion and river bank erosion (the substrate of the Nakha and Kuraburi rivers has changed drastically over the past 10 years, due to erosion. The muddy substrate that facilitates the growth of Water Onion has been replaced by pebbles, rock and gravel, in large areas of these rivers. Collection of bulbs from the wild for sale to the international trade for home fish ponds and aquaria is also a threat which needs closer monitoring.

Licensehttp://creativecommons.org/licenses/by-nc-sa/3.0/
Rights holder/AuthorInternational Union for Conservation of Nature and Natural Resources
Sourcehttp://www.iucnredlist.org/apps/redlist/details/201627

Conservation Actions:

Conservation Actions

The Office of National Environmental Policy and Planning in Thailand (ONEPP) has declared this species as nationally endangered (http://www.onep.go.th/). Local conservation groups in the Ranong province have also initiated the conservation of this species in its wild habitats (Youth group and Plern Prai Sri Na Ca Conservation Group established by Klong Na Ca Wildlife Sanctuary). The youth group is involved in awareness campaigns, ex situ propagation of Water Onion in nurseries, rescue of dislodged Water Onion deposited on river banks and subsequent re-planting in the wild. The Pleun Prai Sri Na Kha Conservation Group, together with the local authority organizes tourist visits (in dinghy paddle boats) along Na Kha river to observe Crinum thaianum during its flowering period (October-December) every year. About 600 Thai tourists visited the area in 2007. A fee of 450 Thai Baht (ca. 15 US$) is charged to each visitor.
Licensehttp://creativecommons.org/licenses/by-nc-sa/3.0/
Rights holder/AuthorInternational Union for Conservation of Nature and Natural Resources
Sourcehttp://www.iucnredlist.org/apps/redlist/details/201627
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