Myriophyllum tetrandrum Roxb., Fl. Ind., ed. 1820 1: 470 1820. (syn. Myriophyllum indicum sensu C.B.Clarke) as per Flora of Eastern Ghats: Hill Ranges of South East India, Volume 3 ; 







Myriophyllum ? from Hooghly 23/11/12 sk: 11 posts by 3 authors. Attachments (8)
Attaching photographs of an aquatic herb that seems to me a Myriophyllum sp.
FBI mentions 5 species : –
  1. M. tuberculatum Roxb.
  2. M. indicum Willd.
  3. M. verticillatum Linn.
  4. M. spicatum Linn.
  5. M. intermedium DC.
Of the above 5 species Bengal Plants mentions the first two, the first one has pink flowers and the second one has white flowers.
Species : Myriophyllum sp.
H & H : submerged aquatic herb in fresh water ditch
Date : 22/11/12, 11.55 a.m.
Place : Hooghly
One fantastic site –, if only we could had one!

Looks like Myriophyllum spicatum to me.

I think it is Myriophyllum indicum Willd.

But it is not reported from Bengal as per IUCN Red List:

excerpts from :-
Bengal Plants i. 474. :-
Myriophyllum tuberculatum Roxb. C. & E. Bengal, in jheels
Myriophyllum indicum Willd. In all provinces in jheels and ponds
F. B. I. ii. 433.
Myriophyllum indicum Willd. Assam & Bengal, in the jheels and canals, common, Coromandel coast and Ceylon
Myriophyllum spicatum Linn. Kashmir, Kumaon
F.I. i. 451.
a native of borders of lakes, and other moist places near Calcutta….
NOT sure who is more authentic… IUCN? Bengal Plants?? F. B. I.??? F.I. ????

Myriophyllum indicum Willd. is 1805 and M.tuberculatum Roxb. 1820 and both mentioned with diagnoses by Prain means two distinct species. Many plants collected by Koenig in Coramandel were included by Linn.f and Wiilld. in Sp Pl. suppl./editions. Type  specimen in Linn Herb. Roxburgh Fl. indica 1820 and Roxb. Icone and if any sp inCAL as type. Sir Prain has seen all collections of Buchanan in Bengal and 60 other collectors who sent specimens to Roxb. some one in Flora Maleiana must have revised this genus for us already. we botanists with Dr Mukrjee just started learning taxonomy from Steenis the  great Taxonomist in Asia. You cannot derermine a species just on the modern media. if Prain satisfctory your identifiction is ok.

If you have two species it is ok. Flora malesina Vol4- onwrds no where in India in 63 Flora Indica itself was known to world due to ED Merrill of USA  Philippines. Bengal Plants is in 1903 and so Prain updated and nomenclature. UNLESS m. tubeculatum ROXB. IS SYNONYM IT STANDS VALID.
APG includes Myriophyllumin Saxifragales and in Haloragaceae So  Engl & Prt lHeft should be checked as they  had revisions which are very important after B*H which are source for Flora Malesiana work in Holland Fl. UUSR and Fl.China started with us as parallel works on warfooting. Only in 68 Dr Nayar returned from Kew and ours work started with only a dozen taxonomits.

This is Myriophyllum tetrandrum Roxb. n synonymous with M. indicum Willd. of ‘Bengal Plants’.




Flora of Eastern Ghats: Hill Ranges of South East India, Volume 3 By T. Pullaiah, K. Sri Ramamurthy (2007- Details with keys- Myriophyllum tetrandrum Roxb. syn. Myriophyllum indicum sensu C.B.Clarke) 
Aquatic and Semi-aquatic Plants of the Lower Ganga Delta: Its Taxonomy … By Kumudranjan Naskar (1990- Details with keys-Myriophyllum indicum Willd. syn. Myriophyllum tetrandrum Roxb.)