Merremia gangetica

• Interesting Facts
• Common Names
• Description
• Taxonomy
• Similar Species
• More Info
• Further Reading
• Notes

Interesting Facts

Common Names

Description

Family Convolvulaceae

Herbs or shrubs , usually with twining or climbing stems or erect , often with milky juice. Leaves alternate, simple , entire, dissected , or compound , absent in parasitic species. Flowers solitary, axillary or in cymes, racemes , panicles, umbels, or capitula, bisexual , actinomorphic , usually 5-merous, often showy. Sepals free , often persistent , sometimes enlarged in fruit. Corolla sympetalous , funnelform , campanulate , salverform , or urceolate ; limb subentire or deeply lobed . Stamens alternating with corolla lobes , adnate to corolla; filaments filiform , equal or unequal in length ; anthers introrse , laterally and longitudinally dehiscing; pollen smooth or finely spiny . Disc ringlike or cupular. Ovary superior, mostly 2-carpellate, 1- or 2-loculed, rarely 3- or 4-loculed; ovules basal, erect. Styles 1 or 2, terminal (gynobasic in Dichondra) or very short or absent; stigma entire or 2- (or 3) -lobed, rarely peltate. Fruit a capsule, dehiscing by valves , circumscissile, or irregularly shattering, less often a berry or nutlike. Seeds usually trigonous , smooth or pubescent .

About 58 genera and 1650 species: widely distributed in tropical , subtropical , and temperate regions ; 20 genera and 129 species in China.

Aniseia biflora (Linnaeus) Choisy and A. stenantha (Dunn) Ling, recognized in the Fl. Reipubl. Popularis Sin., are here treated as Ipomoea biflora and I. fimbriosepala, respectively, because both have pantoporate and spinulose pollen. Strictly speaking, Aniseia is a neotropical genus of about five species, of which A. martinicensis (Jacquin) Choisy is widely naturalized as a common weed in rice paddies in Thailand and other southeast Asian countries. It will probably be found in S China eventually.

The family is important in China for food plants (Ipomoea batatas (Linnaeus) Lamarck and I. aquatica Forsskål), several ornamentals (Ipomoea), several medicinal plants (Erycibe, Ipomoea, Cuscuta, Merremia, Dichondra, Evolvulus), and numerous noxious weeds (Cuscuta, Calystegia, Convolvulus) .

Pollen aperture type and surface ornamentation are important characters in the classification of Convolvulaceae at the generic level and above. The most critical feature of the pollen is whether the grain surface is spiny or not. This distinction separates the eight tribes recognized by Austin (Ann. Missouri Bot. Gard. 60: 306-412. 1973) into two rather cohesive groups. A low magnification (20 ) is adequate for discerning the presence or absence of minute spines on the surface.

For the successful identification of Convolvulaceae, both flowering and fruiting material should be collected. The first key to genera requires adequate fertile material with both flowers and fruit, and requires use of a pollen character. The second key may be used as an aid to identification where material is lacking flowers or fruit, but in some instances it is still partially dependent upon having both flowers and fruit.[1]

Genus Merremia

Herbs or shrubs , often twining , sometimes prostrate . Leaves usually petiolate , rarely sessile, margin entire, dentate , or palmately or pedately lobed or compound . Flowers axillary , solitary or in few- to many-flowered, variously branched cymose inflorescences; bracts usually small. Sepals variable in shape , often convex , subequal or outer 2 smaller, persistent , often enlarged in fruit. Corolla often yellow or white, sometimes with a darker center, funnelform or campanulate , usually glabrous , or midpetaline bands ± sericeous , sometimes only at apex; limb entire or ± 5-angled. Stamens included , often unequal; anthers often spirally twisted; filaments dilated basally, filiform distally; pollen 3-12-colpate or polyrugate, not spiny . Disc ringlike. Pistil included; ovary (imperfectly 2-) 4-loculed, 4-ovuled. Style 1, filiform; stigmas 2-globular. Capsule 1-4-loculed, usually 4-valved or ± irregularly dehiscing. Seeds 4 or fewer, glabrous or pubescent to villous especially at margin.

Approximately 80 species: tropical regions of Africa, Asia, Australia, North and South America; 19 species in China.

The generic name Merremia was published as a nomen nudum by Dennstedt (Schlüssel Hortus Malab. 12, 23, 34. 1818). Several modern floras attribute the valid publication of the name to H. Hallier (Bot. Jahrb. Syst. 16: 581. 1893), but Endlicher (1841) actually validated the name.

Merremia is often confused with Ipomoea, which has pantoporate , spiny pollen, straight anthers and very few species with yellow corollas. It is also confused with Operculina, which consistently has a fruit with a circumscissile lid that detaches first, leaving a fragile endocarp that shatters irregularly. The distribution of hairs on the corolla is taxonomically important in Merremia; this is most easily discerned on mature flower buds.[2]

Habitat

Biome: Terrestrial ; Freshwater[3].

Ecology:  

It is a perennial herb, found in marshes, on the banks of canals and pools where it is frequently inundated (Cook 1996). It is also found  in wastelands, waterlogged areas, roadsides, grasslands, on clay to sandy soils.

[3].

List of Habitats :

•     5     Wetlands (inland)   
  
•     5.1     Wetlands (inland) - Permanent Rivers/Streams/Creeks (includes waterfalls )   
  
•     5.4     Wetlands (inland) - Bogs , Marshes, Swamps , Fens , Peatlands   
  
•     5.5     Wetlands (inland) - Permanent Freshwater Lakes (over 8ha)   
  
•     15     Artificial/Aquatic & Marine   
  
•     15.8     Artificial/Aquatic - Seasonally Flooded Agricultural Land   
  
•     15.9     Artificial/Aquatic - Canals and Drainage Channels , Ditches   
[more info]

Taxonomy

Synonyms

Convolvulus reniformis • Merremia emarginata

Notes

 




[3].

Similar Species

Members of the genus Merremia

ZipcodeZoo has pages for 13 species, subspecies, varieties, forms, and cultivars in this genus:

M. aegyptia (Hairy Merremia) · M. aurea (Yellow Morning Glory) · M. bipinnatipartita (Merremia) · M. cissoides (Roadside Woodrose) · M. discoidesperma (Crucifixion Bean) · M. dissecta (Alamo Vine) · M. gangetica (Kidney Leaf Morning Glory) · M. hederacea (Ivy Woodrose) · M. peltata (Merremia) · M. quinquefolia (Batatilla Blanca) · M. sibirica (Merremia) · M. tuberosa (Hawaiian Woodrose) · M. umbellata (Aguinaldo Amarillo)

More Info

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Further Reading

• Babu, A.V., Rao, R.S.C., Kumar, K.G., Babu, B.H. and Satyanarayana, P.V.V. 2009. Biological activity of Merremia emarginata crude extracts in different solvents. Resesrch Journal of Medicinal Plant 3: 134-140.
• Chatterjee, A. and S.C. Prakashi. 1995. The Treatise on Indian Medicinal Plants. NISC/CSIR, Govt. of India, New Delhi.
• Cook, C.D.K. 1996. Aquatic and Wetland Plants of India. Oxford University Press, Oxford.
• Dave, M. and Krishnayya, N.S.R. 2004. Habitat alteration and floristic changes in and around Harni pond Baroda, India. Tropical Ecology 45(2): 293-301.
• IUCN. 2011. IUCN Red List of Threatened Species (ver. 2011.1). Available at: http://www.iucnredlist.org. (Accessed: 16 June 2011).
• Pratap, G. P., Sudarsanam, G., Jyothi, B. and Prasad, G. P. 2010. Ethnic practices on Urinary Disorders and Jaundice from the Tribes of Nellore District Andhra Pradesh, India. Ethnobotanical Leaflets 14: 976- 985.
• Rajasab, A. H and Isaq, M. 2004. Documentation of folk knowledge on edible wild plants of North Karnataka. Indian Journal of Traditional Knowledge 3(4): 419-429.
• Thakur, A.S. and Khare, P.K. 2010. Vegetation changes during fifty years in the forest-complex of Patharia hills, Sagar, India. Tropical Ecology 51(2): 161-171.
• Fang Rhui-cheng & Huang Shu-hua in Wu Cheng-yih, ed. 1979. Convolvulaceae. Fl. Reipubl. Popularis Sin. 64(1): 1-153.

Notes

Contributors

• Brands, S.J. (comp.) 1989-present. The Taxonomicon. Universal Taxonomic Services, Zwaag, The Netherlands. Accessed January 10, 2012.
• IUCN 2012. IUCN Red List of Threatened Species. Version 2011.2. . Downloaded on January 28, 2012.
• Mani, S. 2011. Merremia gangetica. In: IUCN 2011. IUCN Red List of Threatened Species. Version 2011.2. <www.iucnredlist.org>. Downloadedon 02February2012.

Identifiers

• Biodiversity Heritage Library NamebankID: 5900698
• Global Biodiversity Information Facility Taxonkey: 15389698
• Globally Unique Identifier: urn:lsid:ipni.org:names:270518-1
• IUCN ID: 222882
• Zipcode Zoo Species Identifier: 3349913

Footnotes

1. Ruizheng Fang & George Staples "Convolvulaceae". in Flora of China Vol. 16 Page 271. Published by Science Press (Beijing) and Missouri Botanical Garden Press. Online at EFloras.org. [back]
2. "Merremia". in Flora of China Vol. 16 Page 291. Published by Science Press (Beijing) and Missouri Botanical Garden Press. Online at EFloras.org. [back]
3. Mani, S. 2011. Merremia gangetica. In: IUCN 2011. IUCN Red List of Threatened Species. Version 2011.2. <www.iucnredlist.org>. Downloaded on 02 February 2012. [back]

©2004-2012 David Stang. All rights reserved.