Murdannia vaginata

Trop. & Subtrop. Asia to N. Australia as per WCSP;

Andaman Is.; Assam; Bangladesh; China Southeast; East Himalaya; Hainan; India; Jawa; Nepal; Northern Territory; Philippines; Queensland; Sri Lanka; Thailand; Vietnam as per Catalogue of Life;

Diffuse herbs, 15-60 cm tall, branched from near the base; branches radiating, rooting at the nodes. Leaves sessile, 3-20 x 0.4-1.5 cm, linear or linear-lanceolate, apex acute or subacute; sheaths to 2 cm long, margins ciliate. Panicle lax, terminal. Flowers 8-12 mm across, solitary or 2-4-fascicled in the axils of persistent, 0.8-1.5 cm long, convolute, purplish bracts; pedicels 5-7 mm long, jointed, hirsute. Sepals 3, 4-6 x 2.5-3.5 mm ovate-lanceolate. Petals 3, violet, 4-6 x 3-4 mm, obovate, base cuneate, apex obtuse. Stamens 2 perfect, filaments 3-3.5 mm long, violet, flattened towards base, bearded with long, purple hairs; staminodes 3-4; filaments bearded. Ovary c. 1.5 mm long, globose, 3-gonous; style 2-2.5 mm long, violet; stigma capitate. Capsule 3-4 x 3.5-4 mm, subglobose, trigonous, 3-celled, enclosed in persistent sepals. Seeds 3, 1 in each cell, 2-3 x 2-2.5 mm, hemispheric, rugose, brownish.
Flowering and fruiting: July-February
Moist localities in the plains
India, Sri Lanka and China
(Attributions- Dr. N Sasidharan (Dr. B P Pal Fellow), Kerala Forest Research Institute, Peechi from India Biodiversity Portal)
Herb ID from Bangladesh_SM_4013-2 : 5 posts by 2 authors. Attachments (1)- 927 kb. 
Picture take, Sep,2018 from Sonadia Island, Cox's Bazar  

I think Murdannia sp.

Quite interesting, It appears to be Murdannia vaginata. The ribbed bracts are visible properly. But the glabrous nature of pedicel (although it is not properly visible) makes it unique. 
Can you have access to it, if yes click some good pics of the flower and flowering scape?. Please revert, it will help ID more precisely.