Ludwigia prostrata ?

Ludwigia prostrata Roxb., Fl. Ind., ed. 1820 1: 441 441 1820. (Syn: Isnardia prostrata (Roxb.) Kuntze; Jussiaea prostrata (Roxb.) Lév.; Ludwigia diffusa Hem.;  Ludwigia fruticulosa Blume; Ludwigia leucorhiza Bl.; Nematopyxis fruticulosa Miq.; Nematopyxis prostrata Miq.; Nematopyxis pusilla Miq.; Oenothera alba Noronha) ?;
 
India, Nepal, Laos, Vietnam, Bhutan, Myanmar [Burma] (Yangon), Java, peninsular
Malaysia, Singapore (I), Thailand, Sri Lanka, Assam, Lesser Sunda Isl. (Timor),
Borneo, Philippines (Palawan, Luzon, Negros, Mindanao), Madagascar, Comores,
?Mascarenes, Andaman Isl. (South Andaman Isl.), Nicobar Isl. (Great Nicobar
Isl.), China (Guangxi, Hainan, Yunnan) as per Catalogue of Life;
500-800 m; Tropical Himalaya, India, Burma, east to S. China, Malaysia as per Annotated checklist of Flowering plants of Nepal;

South and SE Asia as per The Genus Ludwigia (Onagraceae) in India by I.C. Barua- Rheedea Vol. 20 (1) 59-70 2010;

Common name: Creeping Water Primrose

Annual herbs to 60 cm tall, often red tinged; branchlets angled and slightly winged. Leaves 3-10 x 0.6-3.6 cm, elliptic to lanceolate, base attenuate, slightly decurrent, apex acute or acuminate, brownish on drying; lateral nerves 8-13 pairs, impressed above and raised below; petiole to 1 cm long. Flowers 5-7 mm across, in the upper leaf axils, solitary or clusters of 2-10 together, subsessile. Sepals 4, 2-2.5 x 1-1.5 mm, ovate-lanceolate, margin ciliate, apex acute, persistent. Petals yellow, 2-3 x 1-1.5 mm, oblanceolate or narrowly spathulate, base cuneate, apex acute, 1-nerved. Stamens 4; filaments c. 1 mm long, yellow; anthers closely appressed to the stigma. Ovary 5-8 x 1 mm, linear, 4-sided, hirsute; style c. 1 mm long; stigma globose, yellow. Capsule 1.2-2 x 0.1-0.15 cm, linear, curved, 4-angled, pale brown, thin-walled, sparsely hirsute or glabrous. Seeds in one row in each locule, c. 0.5 mm long, ovoid, pale pink, transversely striped with fine brown lines.

Flowering and fruiting: June-December
Swampy areas
India, China, Sri Lanka and South East Asia
(Attributions- Dr. N Sasidharan (Dr. B P Pal Fellow), Kerala Forest Research Institute, Peechi from India Biodiversity Portal)
  

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Another small herb of around 1.5 feet height in Mumbai. It has small but one of the most beautiful yellow flowers. Would love to know its id.

Nice pictures of Ludwigia sp., most probably L. perennis.

Excellent images & very interesting post too …
Most likely to be L. prostrata.
This is the most uncommon of the Ludwigia species around Mumbai, please share it’s location.
A word of caution: Ludwigia’s need closer scrutiny for definitive identification down to species level.

This plant confirms the identity of your earlier post of Ipomoea aquatica from similar habitat. Coming to this plant Id: it is Ludwigia species. I remember we had a long discussion with … throwing up light on the key about the Ludwigia species.
Stamens need to be checked carefully.

Thanks a lot … for your responses. The pictures were taken at Kala Nagar in Bandra. In case I happen to see it again, could you please suggest what to check and photograph to be able to identify the species.

I am highly confused with this plant.
I request Iswar Barua ji to help with the id of this plant.
Is it Ludwigia perennis L.? If so, are the images at Ludwigia perennis correctly identified ?
I also request him to pl. comment on other ids, I have marked to him. 

Or is it Ludwigia prostrata Roxb. as fruit appears to be 4 angular, although leaves appears to be different from those give in The Genus Ludwigia (Onagraceae) in India by I.C. Barua- Rheedea Vol. 20 (1) 59-70 2010 (pdf available in this efi thread).

Can you check for Ludwigia octovalvis?
Posted by me earlier and identified as above by …

Thanks, …, I have checked. It is not this species. 

 

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