Justicia prostrata (Roxb. ex C.B.Clarke) Gamble, Fl. Madras

P., Soumya, Y. F., Deng, S. S., Dash & Sunojkumar, P., 2023, A taxonomic revision of the genus JUStICIa (Acanthaceae) in Peninsular India, Rheedea 33 (4), pp. 270-331 : 302-305

Justicia prostrata (Roxb. ex C.B.Clarke) Gamble, Fl. Madras 2: 1081. 1921. L.H.Cramer, Revis. Handb. Fl. Ceylon 12: 115. 1998; V.A.W.Graham, Kew Bull. 43: 597. 1988. Justicia diffusa Willd. var. prostrata Roxb. ex C.B.Clarke in Hook.f., Fl. Brit. India 4: 538. 1885. Rostellularia prostrata (Roxb. ex C.B.Clarke) Majumdar, Bull. Bot. Soc. Bengal 25: 75. 1971. Lectotype (designated by Soumya & Sunojkumar, 2018): INDIA, s.loc., s.d., Roxburgh s.n. (K [K000884088 digital image!]). FigS. 20 & 21

Annual prostrate herbs, up to 30 cm tall. Stems angular, scabrous, dichotomously branched with woody root stock; branches slender, greenish, densely pubescent with strigose hairs on each angle; internodes 1–4 cm long. Leaves petiolate; laminae ovate to elliptic, sometimes orbicular, 0.6–3.5 × 0.7– 1.8 cm, base cuneate or rounded, margins entire, finely ciliate, apex obtuse to acute or rounded, chartaceous, puberulous sometimes densely pubescent; veins prominent, hairy, secondary veins 3–4 pairs, venation eucamptodromous; petioles 0.3–1.5 cm long, puberulous. Inflorescence slender terminal or axillary spike, up to 7 cm long, many-flowered; peduncles 0.75–3 cm long. Flowers sessile, two per inflorescence node, 4–6 × 3–4 mm; bracts ovate to elliptic, 2–3.3 × 0.8–1.3 mm, margin scarious, minutely ciliate, apex acute, greenish, single-nerved, pubescent; bracteoles similar to bracts but narrower, 1.2–2.5 × 0.5 mm. Calyx deeply 5-lobed, 3.5–4 × 1–1.25 mm at anthesis, accrescent, greenish; lobes unequal, the fifth lobe much reduced, 1 mm long; other lobes 3–3.5 × 0.5–0.8, linear–lanceolate, apex shortly acuminate, margins scarious, ciliate. Corolla purplish white with white striations on lower lip, sparsely pubescent outside, glabrous inside except in the throat; tube cylindrical, c. 2 × 1 mm, slightly enlarged at throat; upper lip erect, triangular to ovate, 3–3.5 × 2–2.5 mm, apex acute or emarginate, hooded; lower lip orbicular to obovate, 3.55–4.5 × 3–4 mm, 3–lobed at apex, lobes imbricate, apex acute. Stamens exserted; filaments 2.5–3 mm long, declinate, white, glabrous except base; anther thecae superposed, slightly oblique, elliptic, 0.6–1 mm long, purplish brown with yellowish shades, upper theca dorsally hirsute, lower theca glabrous; appendage c. 0.5 mm long, apex acute or obtuse, white. Ovary ellipsoid, c. 1 × 0.5 mm, pale green, densely pubescent at apex; style slender, 3–3.5 mm long, whitish, hirsute in lower half; stigma simple, capitate; necteriferous disc cup-shaped, c. 0.4 mm high, pale green, glabrous. Capsule oblong or clavate, 3–4 × 0.7–1 mm, pale brown, apex cuspidate, densely pubescent at apex or in lower half. Seeds 4, ovoid to sub-orbicular compressed, 0.7–1 × 0.8–1.3 mm, grooved along the back brownish; testa rugulose.

Flowering & fruiting: Flowering from July to December; fruiting in January.

Habitat: This species is predominantly found in deciduous forests, on grassy hill slopes, plains and along roadsides. It is occasionally observed in sandy areas along the coast and in deep evergreen forests at altitudes of around 250 m.

Distribution: India and Sri Lanka.

Specimens examined: INDIA, Andhra Pradesh, Chittoor district, Sathyavedu, 07.10.1979, M. Chandrabose 45258 (MH); Cuddalore district, Sirupakkam R.F., 08.09.1977, K. Ramamuthy 50700 (MH); Ibid., near Pongala cheruva lake, 20.08.1958, K. Subramanyam 6306 (CAL); East Godavari district, Devipatnam, 25.06.1965, G. V. Subba Rao 24444 (MH); Srikakulam district, Paralakhemundi palace compound, 09.05.1979, G. V. Subba Rao 62370 (CAL, MH); Vishakhapatnam district, Nattuvaranam, 06.1900, C.A. Barber 1837 (CAL); West Godavari district, Kovvur, 20.11.1970, J.L. Ellis 37200 (MH). Karnataka, Bengaluru district, Marathahalli R.F., 18.07.1978, E. Vajravelu 57862 (MH). Kerala, Idukki district, Chinnar, 13.05.2018, P. Soumya, Dilsha, Manu & P. Sunojkumar 157549; Thekkady, 05.11.1993, Jomy Augustine 12522 (CALI); Kollam district, on road sides, 17.07.1912, M.M. Rama Rao 444 (FRC); Thiruvananthapuram district, Neyyanttinkara, near railway track, 05.08.2017, P. Soumya, Shinoj & P. Sunojkumar 157540; NIIST campus front gate, 05.12.2017, P. Soumya, Linu & P. Sunojkumar 157554 (CALI). Maharashtra, Pune district, Daund, 35.11.1956, F. Ujari 9577 (BSI). Tamil Nadu, Chengalpattu district, Vandalur, 25.10.1914, s.coll. 11067 (MH); Vedanthangal W.B. Sanctuary, 26.01.1976, A.N. Henry 47035 (CAL); Chennai district, Chepauk, s.d., Rama Rao , M.P., s.n. (FRC); Barkuda, 27.10.1919, N. Annadale 1342 (CAL); Southern forest rangers college estate, near research block, 09.09.1969, K. N. Subramanian 3777; Villukaradu, 31.08.1910, C.E.C. Fischer 2103 (FRC); Coimbatore district, Agri College, 07.09.1968, M. Chandrabose 29773 (MH); college estate, 20.11. 1967, K. N. Subramanian 192 (FRC); Foot of Kuridimalai, 19.09.1956, K. Subramanyan 774; Maruthamalai, 07.08.1956, K.M. Sebastine 493 (CAL, MH); Nellimalai R.F., 26.05.1962, K. Ramamurthy 14134; Madukkari hill, 09.08.1962, C.P.S. Madhavan 8 (MH); Cuddaloredistrict, Chidambaram park, 04.10.1964, M. Chandrabose 28563 (MH); Dharmapuri district, Marudahalli R.F., 18.07.1978, E. Vajravelu, 57862 (CAL); Erode district, Pioneer estate, 31.07.1966, B.V. Shetty 28057 (MH); Kanchipuram district, Vandalur R. F. Zoological park area, Thambaram Range, 24.08.1982, K. N. Subramanian 8450 (FRC); North Arcot district, vazhiyur, 26.03.1978, E. Vajravelu 55602; Tippukadu R.F., on the road to Markanan, 11.01.1959, K. Subramanyam 7611; Ibid., 0 1.07.1963, K. Ramamurthy 16635 (CAL); Pudukkottai district, Sivaganga, 14.08.1964, K. Ramamurthy 201788 (MH); Sivaganga, 20.08.1964, K. Ramamurthy 21012 (MH); Ramanathapuram district, 25.12.1989, V. Balasubramaniam 2312 (CAL); Salem district, Attur, Chinnakalrayanas, 27.06.1972, N. Venugopal 14410 (CAL); South Arcot district, Paluur, 23.08.1930, s.coll. 4115 (CAL); Marakkanam Pondy route, 20.09.1979, R. Ramamurthy 64188 (CAL); Thanjavur district, Muthupet, 20.05.1978, V.J. Nair 56563; Puthukottai to Aranthangi, 14.09.1979, K. Ramamurthy 51233 (CAL); Theni district, Kambam, 05.1917, Blatter & Hallberg 520 (CAL); Tirunelveli district, Kodumady, 09.07.1959, K.M. Sebastine 8331 (CAL); Tiruvannamalai district, Mamandur valley, 12.10.1958, K. Subramanyam 6912 (MH); Sengaltheri, 26.09.1916, s.coll. s.n.; Naterikal road, 12.02.1913, s.coll. 38405; Sivanaperi, 07.11.1962, J. Joseph 15121; Kayamoli, 27.11.1961, K.M. Subramanyam 13641 (CAL); Viluppuram district, Marakkanam pond route, 20.09.1979, K. Ramamurthy 64188 (MH). Peninsula Indiae Orientalis, Herb. Wight. Propr., 2668 (CAL).

Conservation status: This species is widespread in Peninsular India. Hence it is assessed here as Least Concern (LC).

Notes: Justicia prostrata can be easily separated from J. diffusa and its other varieties by the 5-lobed calyx with the fifth lobe much reduced against an equally 4-lobed calyx.

Figures

Fig. 20. Justicia prostrata (Roxb. ex C.B.Clarke) Gamble: a. Habit; b. Inflorescence; c. Flower; d. Flower bud; e. Bract; f. Bracteoles–abaxial side; g. Calyx; h. Calyx–opened; i. Corolla–opened; j. Upper lip; k. Lower lip; l. Stamens; m. Gynoecium; n. Capsule; o. Seeds (from P. Soumya & P. Sunojkumar 157540;photos by P. Soumya).

Fig. 21. Distribution of Justicia prostrata (Roxb. ex C.B.Clarke) Gamble in Peninsular India.Drawn using R (R Core Team,2023).