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Aerva triangularifolia

Interesting Facts

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Description

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Family Amaranthaceae

Herbs, clambering subshrubs , shrubs , or lianas. Leaves alternate or opposite, entire, exstipulate . Flowers small, bisexual or unisexual , or sterile and reduced, subtended by 1 membranous bract and 2 bracteoles, solitary or aggregated in cymes. Inflorescences elongated or condensed spikes (heads ), racemes , or thyrsoid structures of varying complexity. Bracteoles membranous or scarious . Tepals 3-5, membranous, scarious or subleathery, 1-, 3-, 5-, or 7(-23) -veined. Stamens as many as tepals and opposite these, rarely fewer than tepals; filaments free , united into a cup at base or ± entirely into a tube , filament lobes present or absent, pseudostaminodes present or absent; anthers (1- or) 2-loculed, dorsifixed , introrsely dehiscent . Ovary superior, 1-loculed; ovules 1 to many; style persistent , short and indistinct or long and slender; stigma capitate, penicillate , 2-lobed or forming 2 filiform branches. Fruit a dry utricle or a fleshy capsule, indehiscent, irregularly bursting, or circumscissile. Seeds lenticular , reniform , subglobose, or shortly cylindric , smooth or verruculose .

About 70 genera and 900 species: worldwide; 15 genera (one introduced ) and 44 species (three endemic, 14 introduced) in China.

Morphology of the androecium, perianth (tepals), and the inflorescence has traditionally been used to circumscribe genera and tribes . Pseudostaminodia are interstaminal appendages with variously shaped apices. Filament appendages are the lateral appendages of filaments (one on each side) . The basic structure of the inflorescence is the cyme (branchlets arising from the bracteole axils, the bracteoles serving as bracts for upper flowers), which can be reduced to one flower with two bracteoles and a bract. Units of dispersal vary considerably (capsules opening with lower part persistent, flower and bracteoles falling together, or cymose partial inflorescences breaking off above bract) and can be characteristic for genera. Several genera possess long trichomes serving dispersal at the base of the tepals.[1]

Genus Aerva

Herbs or subshrubs . Stem erect , stoloniferous or climbing . Leaves alternate or opposite, margin entire. Flowers perfect , unisexual or dioecious, small or very small. Inflorescences spikes, terminal or axillary , simple or in complex thyrsoid structures. Bracts and bracteoles membranous, persistent or bracteoles falling off with perianth in fruit. Tepals 4 or 5, ovate or oblong , membranous or papery , lanose, with only 1 vein . Stamens 4 or 5; filaments subulate , unequal, united to short cup at base , alternating with pseudostaminodes, pseudostaminodes subulate to oblong; anthers 2-loculed. Ovary obovoid or subglobose, glabrous ; style persistent; stigmas 2, capitate. Utricles ovoid , compressed , membranous, indehiscent or irregularly dehiscent (bursting), falling off with perianth. Seeds reniform-orbicular, lenticular , compressed.

About ten species: Africa, Asia; two species in China.[2]

Taxonomy

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Notes

Publishing author : Cavaco Publication : Bull . Soc. Bot. France 99: 253 1953

Similar Species

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Members of the genus Aerva

ZipcodeZoo has pages for 3 species, subspecies, varieties, forms, and cultivars in this genus:

A. javanica (Java Aerva) · A. lanata (Aerva) · A. sericea (Island Puzzle)

More Info

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Further Reading

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Notes

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Contributors

Data Sources

Accessed through GBIF Data Portal November 15, 2007:

Identifiers

Footnotes

  1. Bojian Bao, Thomas Borsch & Steven E. Clemants "Amaranthaceae". in Flora of China Vol. 5 Page 415. Published by Science Press (Beijing) and Missouri Botanical Garden Press. Online at EFloras.org. [back]
  2. "Aerva". in Flora of China Vol. 5 Page 422. Published by Science Press (Beijing) and Missouri Botanical Garden Press. Online at EFloras.org. [back]
Last Revised: 7/22/2012