Hymenachne amplexicaulis

Hymenachne amplexicaulis (Rudge) Nees, Fl. Bras. Enum. Pl. 2: 276 1829. (Syn: Agrostis monostachya Poir.; Hymenachne acutigluma (Steud.) Gilliland; Hymenachne gouinii E.Fourn.; Hymenachne monostachya (Poir.) P.Beauv. [Invalid]; Hymenachne pseudointerrupta C.Muell.; Panicum acuminatum Salzm. ex Döll [Invalid]; Panicum acutiglume Steud.; Panicum acutiglumum Steud.; Panicum amplexicaule Rudge; Panicum amplexicaule var. deflexum Döll; Panicum amplexicaule var. erectum Döll; Panicum amplexifolium Griseb. ex Mez; Panicum auritum Hassk. [Illegitimate]; Panicum caudatum Willd. ex Steud. [Invalid]; Panicum grisebachianum Mez; Panicum hasskarlii Steud. ex Zoll.; Panicum hymenachne Desv.; Panicum myurum G.Mey.; Panicum perdensum Steud.; Sporobolus villosus Hochst. ex Döll [Invalid]);
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grass Hymenachne sp. from Hooghly 13/11/12 sk1:

Searched for aquatic grass and found :-

Flora of Taiwan has a species, Hymenachne pseudointerrupta – eflora
According to The Plant List H. pseudointerrupta is a synonym of H. amplexicaulis – http://www.theplantlist.org/tpl/record/kew-419692
GRIN has H. acutigluma that includes H. pseudointerrupta – http://www.ars-grin.gov/cgi-bin/npgs/html/taxon.pl?405756
This site informs Hymenachne pseudointerrupta is a fodder grass in West Bengal – http://www.fao.org/docrep/004/X6532E/X6532E05.htm
This document says H. acutigluma is found in wasteland – Academia

Pictures of H. amplexicaulis :-

Pictures of H. pseudointerrupta :-

Picures of H. acutigluma :-

Flickr

Species : Hymenachne acutigluma (Steud.) Gilliland ?

H & H : grass on the edge of water-body; prostrate-erect stem, about 3 feet or less, glabrous; leaves more than 15 cm x 1 cm, upper surface sightly hairy, lower surface glabrous; inflorescence 18 cm or longer.

Date : 10/11/12, 1.45 p.m.

Place : Hooghly

Yes it is Hymenachne acutigluma. All the synonyms refers to the same species. I will check the priority of the basionyms Panicum acutigluma and P.amplexicaule and let you know what the specific epithet should be as per rules. This is a grass found in semi aquatic to aquatic conditions and can be found in different variations of size of leaves and inflorescence. When growing in drainage nalas with lot of nutrition, it can assume even gigantic forms.

Earlier, i rejected Hymenachne pseudointerrupta and Hymenachne amplexicaulis because internet shows deeply cordate & clasping leaf-base.

And, i do have some long-shot of another grass, might be the same, growing in drainage nala, with more robust inflorescence. Will upload later.