Thalia dealbata Fraser ex Roscoe, Trans. Linn. Soc. London 8:340. 1807 (syn: Malacarya dealbata (Fraser) Raf.; Maranta dealbata (Fraser) A.Dietr.; Peronia stricta Redouté; Spirostalis biflora Raf.; Spirostylis biflora Raf.; Thalia barbata Small);

Thalia dealbata (Powdery thalia, Hardy canna, Powdery alligator-flag) is an aquatic plant in the family Marantaceae, native to swamps, ponds and other wetlands in the southern and central United States.[2][3][4] Its range includes much of Coastal Plains and the lower Mississippi Valley (States of South Carolina, Georgia, Alabama, Mississippi, Louisiana, Texas, Oklahoma, Arkansas, Missouri, Illinois and Kentucky).[5] The plant has been grown as an aquatic ornamental because of the pretty violet flowers, and in cultivation has been proved hardy as far north as Philadelphia (Pennsylvania) and Vancouver (British Columbia).[6][7][8]

Thalia dealbata grows to 6 ft (1.8 m), with small violet flowers on an 8 in (20 cm) panicle held above the foliage. The blue-green leaves are ovate to lanceolate, dusted with white powder and with purple edges.[9][10]
(from  Wikipedia on 7.6.15)



Thalia dealbata Fraser ex Roscoe, Trans. Linn. Soc. London 8:340. 1807
Powdery Thalia, Powdery Aligator Flag
Aquatic plant of shallow waters, with basal lanceolate-elliptic to oblong-ovate leaves on long petioles; flowers small, purple, crowded in narrow panicles, at tip of up to 3 m long scape, subtended by purple bracts; sepals 3, corolla 3-lobed, or nearly divided.
Photographed at Plantae Paradise, Datya Vill., near Parwanu, along Shimla Road.

Another from Churdhar trip



SK398 03MAR-2017:ID : 7 posts by 2 authors. Attachments (5)

Location: Shanghai, China
Altitude: 100 -200 ft.
Date: 29 October 2014

Some Alpina sp..??

May be a Marantaceae member. 

Thank you …!  Thalia dealbata Fraser (accepted name)



GRIN  The Plant List Ver.1.1
(unresolved) Tropicos  Wikipedia  Dave’s Garden