Gymnostachyum ceylanicum

An indigenous herb common under shade in intermediate zone forests, often in rocky grounds. Flowering from March to August. 

Rostellularia mollissima [Syns: Rostellularia latispica, Justicia procumbens subsp. latispica]

Common native annual herb grows among grass on the slopes of patana lands of the montane areas, generally above 2000 m a.s.l. Flowering throughout the year. 

Mountain thistle (Acanthus montanus)

 
Large prickly herb native to West Africa. Cultivated as an ornamental plant and also possibly escaped and naturalized in the hill country waste places and roadsides.   

ආඩතෝඩ/අගල් ආධාර/පාවට්ටා/වන ඇපල[Adathoda/Agal adara/Pavatta/Wana epala]/Common Cough Cure/Malabar Nut(Justicia adhatoda)

 Common native shrub cultivated as a hedge plant and occasionally on borders of paddy fields in the low and mid country. Widely used in traditional and Ayurvedic medicine as a remedy to cough, asthma, phlegm and fever with several other plant elements.  

Barleria arnottiana

 An indigenous shrubby herb common in the undergrowth of montane forests close to water courses. Flowering from September to April with a peak in October and November  ( var. arnottiana)

var. glabra - Grows in Low and intermediate country. Flowering from November to February.

 

Mexican wild petunia/Desert petunia (Ruellia simplex)

 An introduced herb or subshrub native to Mexico and South America. Cultivated in home gardens and occasionally escaped and naturalized. 

Justicia scandens [Syn: Justicia glabra]

An indigenous undershrub of mid country moist places. Flowering from January to April. 

Lepidagathis ceylanica

Rathe rare endemic herb of moist mid country. Flowering from March to July and November. It was considered as a Critically endangered (Possibly extinct) species in the 2012 National Red List.

Lepidagathis walkeriana

 An endemic shrubby herb grows under shade in busy localities in sub montane and moist mid country. Often grows on embankments bordering disturbed submontane forests. Rather common and flowering from March to November. 

Strobilanthes habracanthoides

An endemic and rare undershrub grows by the streams in moist south western hill forests from 650 to 1300 m elevations.

Dicliptera neesii

An endemic prostrate herb grows among grasses in under shade of secondary dry lowland forests. Often occurs close to streams. Flowering from May to August.

Dicliptera japonica [Syn: Peristrophe japonica]

An indigenous (?) prostrate herb grows among grass in light shade of the Northern dry and intermediate regions.

*An addition to the flora of Sri Lanka by J. &J.  de Vlas, 2008
*** With the J. & J. deVlas, 2019 this plant was re-identified as endemic Dicliptera neesii. So that Peristrophe japonica is no longer a plant species occurs in Sri Lanka. 

රන්වන් කටු කරඩු[Ranwan Katukarandu] (Barleria lupulina)

An introduced small shrub native to the Mauritius. Cultivated as a hedge plant in home gardens. 

Phaulopsis dorsiflora [Syn: Phaulopsis imbricata]

Common native herb with straggling hairy stems, grows close to the streams of dry and moist lowland secondary forest undergrowth. Flowering from December to May.

Flower Size - 0.3-0.4 cm across

Black-eyed Susan (Thunbergia alata)

An introduced climber native to tropical East Africa. Cultivated as an ornamental. An escape from Botanic Gardens and naturalized along roadside embankments, tea plantations etc. Common in moist areas and hill country up to about 1500 m a.s.l. Flowering from August to February.

හීන් බිං කොහොඹ[Heen Bin Kohomba] (Andrographis paniculata)

Very rare indigenous herb considered as a Critically Endangered (Possibly Extinct) in the 2012 Red list. However Jayasinghe H.D. has reported it in a home garden at Hammaliya of the Kurunegala district in 2013-14. Pictures posted with this post were observed at a roadside embankment at Dondra (දෙවිනුවර/දෙවුන්දර) of Matara district in mid of December 2017 with flowers. Several plants were seen in the vicinity. As per Dasanayaka M.D. & Clayton W.D. two varieties of this herb occurs in Sri Lanka. Variety paniculata grows in semi-shade in waste places by roadsides in the moist and dry lowlands and moist mid country, while endemic variety glandulosa is found in sub-montane forests. Flowering from January to April. Whole plant medicinal. 

References:

• Dasanayaka M.D. & Clayton W.D., 1998, A Revised Handbook to the Flora of Ceylon, Volume XII
• The National Red List 2012 of Sri Lanka; Conservation Status of the Fauna and Flora. Weerakoon, D.K. & S. Wijesundara Eds.,Ministry of Environment, Colombo, Sri Lanka. 99-113 pp
• Jayasinghe H.D., 2015 Notes on observations of some threatened flowering plants of Sri Lanka including two “Extinct” species.Himesh Dilruwan Jayasinghe, NeBIO I An international journal of environment and biodiversity Vol. 6, No. 2, June 2015, 1 - 8

අනිත්ත[Aniththa] (Rhinacanthus flavovirens)

Rhinacanthus flavovirens is a recently described endemic perennial herb distributed in secondary forests of North Central, Central and Southern province dry lowlands. It occurs under shade of trees close to watercourses.

Reference : Amarasinghe A.P.P.R.& Wijesundara D.S.A., 2011, A new species of rhinacanthus (Acanthaceae) from Sri lanka, Edinburge Journal of Botany 68(3): 333-337 (2011)

Justicia tranquebariensis

Common native herb or small undershrub grows in light shade among rocks or in sandy ground among short grass in the dry lowlands. Flowering from January to September.

නෙළු[Nelu] (Strobilanthes diandra)

An endemic under-shrub grows in primary and secondary montane forests and scrubs mainly in the northern part of the Kandy district from 900-1600 m a.s.l.

බූ නෙළු[Bu Nelu](Strobilanthes cordifolia [Syn: Stenosiphonium cordifolium])

An indigenous small shrub grows along streams and river banks of secondary forest undergrowth in the dry and intermediate zones. Common and gregarious plant flowering from December to April.