Andrographis atropurpurea

Andrographis atropurpurea (Dennst.) Alston, Taxon 26: 539 1977. (Syn: Andrographis gracilis Nees; .; Justicia atropurpurea Dennst. (Unresolved)); 

Suberect undershrubs; stems hairy. Leaves to 10 x 4 cm, ovate, acuminate, broadest at base, glabrous; nerves 4 or 5 pairs, subprominent; petiole 0-5 mm long. Panicle with long lax racemes, scabrid; bracts and bracteoles subulate. Flowers distant; calyx lobes 5 mm long, subulate, hairy; corolla 18 mm long, glabrous, upper lip orbicular, retuse, dark brown, lower lip shallowly lobed, light pink with brown spots; lower anther bases bearded. Capsule 22 x 3 mm, oblong, glandular hairy; seeds 8, orbicular, glabrous.
Flowering and fruiting: July-September
Openings in evergreen and semi-evergreen forests
Western Ghats (Endemic)
(Attributions- Dr. N Sasidharan (Dr. B P Pal Fellow), Kerala Forest Research Institute, Peechi

Images by Anurag N. Sharma, Identified by P. Santhan (Inserted by J.M.Garg)
ANDEC31 Andrographis sp. for identification : 5 posts by 3 authors. Attachments (7).
Chimmony Wildlife Sanctuary, Kerala
November 2014

a paniculata most likely
I have tow growing in my flower pot, volunteered plant

Andrographis atropurpurea (Dennst.) Alston
without the key... the flower's largest petal has different shape and color
i looked at my balcony flowers they are different in this detail

Images by Ranjini Kamath, Identified by Santhosh Kumar (Inserted by J.M.Garg)
Wild Flower for Bot. ID-080110-RK-2 : 6 posts by 4 authors. Attachments (2)
Less than 1cm across. Found at base of Kallipaara Hill, Thattekad, Kerala. Pic taken on11-12-09 at 9.30am. Request ID. Thank you.
this is Andrographis (Acanthaceae). We need more details like habit, leaves, etc to tell you the species name.
Thank you v. much ... I was v. keen on getting the id of this flower. I thought this plant was only one of it's kind!-& hence easily identifiable. I have taken pictures of this from different places in Thattekad & will send them after going thro' them in order to get the complete ID.
Here are some more photographs. The first one are leaves of the plant i have already sent a pic of & taken at base of Kallipara hill at the same time. The last three were taken in Edamalayar Forest on 09-12-09 at around 7.15 am. I hope these can help towards arriving at a clearer ID. The first one had actually appeared more elongated & i was mistaken in writing the size -which applies more to the 2nd set of pictures.
Attachments (4) 
Andrographis sps.
Seems to be Andrographis atro-purpurea [= A. wightiana]
I guess correct ID