Justicia gambleana K.M.P.Kumar, Robi & Hareesh, Phytotaxa

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 : 282-286

Justicia gambleana K.M.P.Kumar, Robi & Hareesh, Phytotaxa 39: 71. 2016. Type: INDIA, Kerala, Palakkad district, Dhoni forest, way to Korakkalu , 26.09.2013, K.M. Prabhukumar 7547 (holo CMPR!; iso CALI, CATH, MH [ MH00003372 !]). FigS. 6–8

Annual erect or decumbent herbs, to 90 cm tall. Stems angular, base woody, dichotomously branched; branches slender, diffuse, greenish, sparsely pubescent to dense white tomentose; internodes 1–7 cm long, purplish. Leaves petiolate; laminae elliptic to ovate or orbicular 1.25–5.5 × 1.2– 3.7 cm, base cuneate to obtuse or oblique, margins entire or sub-crenate, ciliate, apex acute to obtuse or sub-acuminate, chartaceous, glabrous to densely pubescent, secondary veins 3–6 pairs, venation eucamptodromous; petioles 0.4–1.5 cm long, pubescent. Inflorescence terminal or axillary spike, slender, dense or lax, 2.5–8 cm long; peduncles short, 0.3–3 cm long, pubescent. Flowers sessile, two flowers per floral node, 5.5–7 × 3–4 mm; bracts linear to narrowly lanceolate or triangular, 1.5–3.8 × 0.4–1 mm, margins scarious, minutely ciliate, apex narrowly acute, greenish, glabrous; bracteoles similar to bracts but narrower, 2–3.5 × 0.5–0.8 mm. Calyx deeply 4-lobed, 3–3.7 × 1–1.5 mm at anthesis, accrescent, 3.8–4.5 × 3–4 mm in fruits, greenish; lobes linear to lanceolate, equal, margins scarious, ciliate, apex narrowly acute, glabrous. Corolla white or purplish white with white striations on lower lip, sparsely pubescent outside, glabrous inside except in the throat; tube cylindrical,2–2.5× 1–1.3 mm,slightly enlarged in throat, white; upper lip erect, triangular to ovate, 2.2–3 × 1.7–2.2 mm, apex minutely 2-lobed, slightly hooded; lower lip orbicular to obovate, 3.5–5 × 3–4 mm, 3-lobed; lobes ovate, imbricate, middle lobe slightly wider than lateral lobes, apex rounded. Stamens exserted; filaments. 1.5–2.5 mm long, declinate, white, basally villous; anther thecae superposed, equal or sub-equal, elliptic, c. 0.5 mm long, purplish brown with yellow shades, upper theca muticous, dorsally hirsute, lower theca glabrous; appendage 0.5–0.7 mm long, apex acute or obtuse, white. Ovary ellipsoid, 1–1.5 × 0.5 mm, pale green, hirsute at apex; style slender, 3–3.5 mm long, whitish, hirsute in lower half; stigma slightly bilobed; nectariferous disc c. 0.5 mm tall, pale yellow. Capsule clavate to fusiform, 4–5.5 × 1–1.75 mm, apex cuspidate or acute, pale brown, glabrous or slightly pubescent at apex. Seeds 4, compressed, cordate to ovate, oblong or sub-orbicular, 0.75–1.5 × 0.8–1.3 mm, pale brown to dark brown; testa rugulose.

Flowering & fruiting: Flowering from July to February; fruiting March.

Habitat: This species grows on moist rocks, in wet humus along Ghat roadsides, hill slopes, stream banks and rock crevices in grasslands at elevations ranging from 350 to 1300 m. It can be seen as undergrowth in moist shady parts of evergreen forests.

Distribution: It is distributed throughout Eritrea to Ethiopia in East Africa, southern Arabian Peninsula, Indian Subcontinent to South China, Indo-China, and Taiwan.

Specimens examined: INDIA, Andhra Pradesh, Chittoor district, Kakuladibba , 31.12.1975, G. V. Subba

Rao 46895 ( CAL); Talakona waterfall, 03.08.2018, P . Soumya, Geethika & P . Sunojkumar 157524 ( CALI); East Godavari district, Devarkonda , 07.10.1920, V . Narayanaswami 473 ( CAL); Kadapa district , s.loc., 07.1884, J. S . Gamble 15190; Nellore district , Inukurthi, 11.1898, T. L . Walker s.n.; Udayagiri, 28.08.1917, s.coll. 4144 ( CAL); Srikakulam district , Saluru forest , 10.09.1962, N. P . Balakrishnan 1081 ( CAL); Vishakhapatnam district, Sunkarametta , 29.08.1960, Subba Rao , G. V . 10929 ( CAL). Karnataka, Bellary district, Sanduru , 10.01.1980, B. R . Ramesh & S. B . Manohar 10717 ( CAL); Bengaluru district, Devanahalli , 30.11.1905, C. E. C . Fischer 484 ( CAL); Chamarajanagar district, Bandipur , 24.08.1964, B . D. Naithani 21115; Ibid. , 25.08.1964, B . D. Naithani 21190 ( MH); Ibid. , Gundlupet, 10.1910, A . Meebold 11435 ( CAL); Haveri district , Byadgi, 12.1888, W. A . Talbot 1775 ( CAL); Uduppi district, Kollur hills, 01.09.1913, M . Ram Rao 1592; s.loc., 10.1910, A . Meeblod 1140 7 ( CAL). Kerala, Idukki district, Karimanal , 12.09.2016, P . Soumya, Drisya & P . Sunojkumar 138522; Kumily , 06.11.1993, Jomy Augustine 12546; Peerumade, 12. 1910, A . Meebold 12905 ( CAL); Ramakkalmedu 08.08.2017, P . Soumya & P . Sunojkumar 138511; Ibid. , 18.09.2018, P . Soumya & P . Sunojkumar 138524; Thekkady, 28.05.1995, Jomy Augustine 15312 ( CALI); Kollam district , Thannithode , 10.08.1984, C. N . Mohanan 69317 ( CAL); Palakkad district, Aruvanpara , 21.08.1982, Sabu, T . 10669 ( CALI); Dhoni hills, 19.01.1910, C. E. C . Fischer 1596 ( FRC, CAL); Ibid. , 26.09.2013, Prabhukumar K. M . 07547, 07549 ( CMPR); Ibid. , 17.08.2018, P . Soumya, Sasikumar & P . Sunojkumar 157528 ( CALI); Gudaloor road, 02.10.1981, Philip Mathew 28799 ( CALI); Malampuzha, s.d., Robi A. J . 07029 ( CMPR); Mannarkkad, Perumalmedu , 23.10.2011, K. A . Anilkumar 4124; Mannarkkad , 10.10.2012, K. A . Anilkumar 4605; Ibid., Varadimala , 30.04.2008, K. A . Anilkumar 3032 ( CMPR); Ibid., Venthapetty , 09.10.2007, K. A . Anilkumar 2390 ( CMPR); Nelliyampathy, near Pothundy dam, 19.09.2013, Prabhu kumar, K. M . 07375; Ibid. , 19.09.2013, Prabhu kumar K. M . 07354( CMPR); Ibid., way to Minnampara , 21.09.2013, Prabhu kumar, K. M . 07540 ( CMPR); Ibid. , 15.10.2017, P . Soumya & P . Sunojkumar s.n. CU138543 ( CALI); Silent valley , 30.08.1983, S . Chand Basha 9573 ( FRC); Walayar range, Varalapadi , 18.09.1975, K. N . Subramanian 5336 ( FRC); Pathanamthitta district, Ranni forest division, Pamba-Kalkki dam site, 25.01.1984, N . Venkatasubramanian 10342 ( FRC); Wayanad district, Periya, Gurukula , 21.07.2016, P . Soumya & P . Sunojkumar 145381 ( CALI); Puthurvayal, 08.04.2001, Ratheesh Narayan M. K 2528 ( CALI); Thiruvananthapuram district , s.loc., s.d. C. C . Calder & M. S . Ramaswami 1583( CAL). Maharashtra, Buldhana district, Lonar lake area, 24.11.1983, P. G . Diwakar 171218 ( BSI); Pune district, Ranipur , 10.08.1965, R . D. Pataskan 101409; Ibid. , 19.08.1965, R . D. Pataskan 105844 ( CAL); Shivneri hill, East Junnar, 27.01.1965, Hemadevi 89976 ( CAL). Tamil Nadu, Coimbatore district , Karadimadai , 30.07.1929, S. R . Raja & Ratnavelu 1950 ( MH); Siruvani, Adivaram bamboo experimental plot, 02.07.1963, K. N . Subramanian 780; Valparai road from Aliyar dam, near five miles, 24.08.1963, K. N . Subramanian 787 ( FRC); Velliangiri mountains , 22.02.1957, K. M . Sebastine 2423 ( CAL); Ibid. , 12.08.2017, P . Soumya, Nikhil, Pradeep A. K. & P . Sunojkumar 138500 ( CALI); Dharmapuri district, Harur, Sitheri hills, 12.08.1978, K. M . Matthew 16675 ( CAL); Dindigul district, Kodaikanal shola, 16.07.1912, s.coll. 52 ( CAL); Erode district , Kodumudy , 10.07.1959, K. M . Sebastine 8421 ( CAL); Sathy Taluk, Dhimbam to BannariGhat road, 24.01.1987, N . Venkatasubramanian N. V . 235; Ibid. , hairpin bends 27-26, 4.10.1987, N . Venkatasubramanian N. V . 842; Ibid., s.d., N . Venkatasubramanian N. V . 456 ( FRC); Krishnagiri district, Denkannikotta, Thally hills, 10.09.1978, K. M . Mathew & N . Venugopal 17325 ( CAL); Namakkal district, Kolli hills, 20.04.1978, A . Mohan 13218 ( CAL); Rasipuram , 31.07.1978, N . Venugopal 15893; Maisor & Carnatic, Herb. Ind. Or. Hook f. & Thomson s.n. ( CAL); Nilgiris district, Coonoor , 11.02.1899, D. I . Prain s.n. ( CAL); Ibid., 10.1910, s.coll. 12016, 12026; Kotagiri, Aravenu , 24.10.1956, K . Subramanyan 1104 ( CAL); Ibid., Mamaram, 06.01.1957, s.coll. 1972 ( CAL); Ooty , Needle view point, 02.01.2017, Shinoj, P . Soumya & P . Sunojkumar 145340; Ibid. , 03.09.2018, P . Soumya & P . Sunojkumar 145361; Salem district, Yercaud , Shevareys lake side, 07.11.1978, N . Venugopal 19066 ( CAL); Tenkasi district, Courtallam , 29.06.1901, C. A . Barber 3294 ( CAL); Tiruchirappalli district, Pachaimalai hill top 06.08.1958, K. M . Sebastine 6165 ( CAL); Tirunelveli district, Manjolai , 05.09.2018, Shinoj, P . Soumya & P . Sunojkumar 157539 ( CALI); Tiruvannamalai district, Javadi hills, 22.11.1975, K. N . Subramanian 95582 ( FRC); Pattarikad R. F ., Polur range, 21.11.1975, K. N . Subramanian 5488 ( FRC); Vellore district, On the way to Kambukudi , 08.09.1958, K . Subramanyam 6491 ( CAL); Tenkasi district, Sengottai to Aryankavu , 08.09.1913, C. C . Cader & M. S . Ramaswami 661; Courtallam falls , 23.07.1957, K. M . Sebastine 3753 ( CAL). Peninsula Indiae Orientalis, Herb. Wight. Propr. 662 ( CAL) .

Conservation status: This species is distributed across all Indian states; thus, it is assessed here as Least Concern (LC).

Notes: This highly variable species exhibits significant morphological diversity across altitudes. The height ranges from 30–90 cm, with sessile to petiolate leaves that vary in shape from linear to ovate or orbicular. Occasionally, white flowers were also observed. At high altitudes (above 1000 m), the plants are shorter and grow from a woody rootstock with compact internodes and smaller leaves. When grown in a greenhouse at lower altitudes, these plants’ shorter habit, internodal length and leaf size gradually mature into the typical herbaceous form, after a few flowering seasons.

Clarke (1885) treated Rostellaria hedyotidifolia Nees as Justicia diffusa var. hedyotidifolia (Nees) C.B.Clarke distinguishing it by its woody stems, petiolate and ovate leaves, short and dense spikes with ciliate sepal tips. However, these characters are observed in the typical variety J. diffusa . The same situation applies to J. diffusa var. orbiculata C.B.Clarke characterised by ovate, petiolate leaves with dense hairs. A woody nature, along with more or less ovate, petiolate leaves and short dense spikes can be observed in J. diffusa from high-altitude regions. Considering the degree of fluctuation in morphological characters linked to altitudinal differences (below 350 & 1300 m), all these varieties were treated as synonyms of J. diffusa .

Figures

Fig. 6. Justicia diffusa Willd.:a. Habit; b. Inflorescence;c. Flower;d. Flower bud;e. Bract;f. Bracteoles–abaxial (left) and adaxial side (right); g. Calyx; h. Calyx–opened; i. Corolla–opened; j. Upper lip; k. Lower lip; l. Stamens; m. Gynoecium with nectariferous disc; n. Capsule; o. Seeds (from P.Soumya & P. Sunojkumar 138500;photos by P. Soumya).

Fig. 7. Justicia diffusa Willd.: a–e: Variations in Habit and Leaf

Fig. 8. Distribution of Justicia diffusa Willd.in Peninsular India.Drawn using R (R Core Team,2023).