Journal of Threatened Taxa | www.threatenedtaxa.org | 26 February 2025 | 17(2): 26562–26565

 

ISSN 0974-7907 (Online) | ISSN 0974-7893 (Print) 

https://doi.org/10.11609/jott.9213.17.2.26562-26565

#9213 | Received 15 June 2024 | Final received 21 November 2024 | Finally accepted 07 February 2025

 

 

Invasive record of Brazilian Petunia Ruellia elegans Poir. (Acanthaceae) from northeastern India

 

Mamita Kalita

 

Department of Botany, Digboi College (Autonomous), Digboi, Assam 786171, India.

mamita.bot@gmail.com

 

 

 

Abstract: The present study reports the invasive occurrence of Ruellia elegans Poir. from northeastern India. The beautiful red flowered species flourishing in Digboi, Assam is marked as its new distribution extension. The occurrence has been documented as a new distribution record for the flora of Assam as well as northeastern India. A detailed morphological depiction, photographic images, characterization and taxonomic notes have been provided to aid in its identification and recognition.

 

Keywords: Assam, biodiversity, conservation, distribution record, flora, floral attributes, identification, morphology, native,  taxonomy, threatening.

 

 

 

The Brazilian Petunia Ruellia elegans Poir. belongs to a morphologically diversified tribe Ruellieae Dumortier. According to Angiosperm Phylogeny Group (APG), Ruellieae appertain in the sub-family Acanthoideae Eaton of family Acanthaceae Jussieu nom. cons. (Stevens 2001 onwards).  As stated in Plants of World Online (POWO 2024) database, Acanthaceae contributes 208 genera and is one of the diverse plant families with estimation of approximately 4,900 species (Manzitto-Tripp et. al. 2021). Members of the genus Ruellia Plum. ex. L. are mostly herbs, shrubs, rarely trees or lianas (Tripp 2007). The genus is horticulturally important having 350 species (Tripp et. al. 2013). However, according to POWO (2024), the genus is portrayed with 365 species distributed in tropics to subtropics to North America. As mentioned by Tripp (2007), the species of Ruellia exhibit remarkable diversity in floral color, size and shape of corolla lobes, tubes, throat. According to Zhuang & Manzitto‑Tripp (2022), the genus Ruellia manifests diversification in floral color due to anthocyanin biosynthetic pathway (ABP) and R. elegans was characterized with both pelargonidin and cyanidin pigments. The species R. elegans Poir. is native to northern, northeastern, and southeastern Brazil, predominantly thriving in wet tropical biome. Further, it has been introduced in regions of Andaman Islands, Puerto Rico, and Jamaica (POWO 2024).

In accord with POWO (2024), India is represented with six native species of Ruellia viz., R. beddomei C.B.Clarke., R. ciliata Hornem., R. malabarica Kostel., R. patula Jacq., R. pseudopatula Ensermu., R. sibua (Nees) I.M. Turner., and R. sivarajanii Sreedevi, Remadevi & Binojk. Whereas, R. ciliatiflora Hook., R. simplex C.Wright., R. tuberosa L. are non-native and introduced species of India. R. elegans is an indigenous species of Brazil (north-east, south, south-east) and introduced in the regions of Andaman Islands, Jamaica, and Puerto Rico. However, the species existence has been marked from Odisha, as a new recorded distribution for eastern India (Kalidass et. al. 2016). According to Ezcurra (1993), the species distribution has extended due to human activities.

 

Materials and Methods

On 19 September 2023, the specimen has been allocated from the vicinity of Dehing Patkai rainforest of Digboi, Assam. Field photographs and GPS location were recorded with help of Canon IXUS 190. The vegetative and reproductive features of the collected specimen were examined through a stereo-zoom binocular microscope (Labomed CZM4). The identity of the species was confirmed through its protologue, and herbarium records. The photoplates were prepared using Adobe Photoshop software (version 7.0). The voucher specimen has been prepared following the protocol of Jain & Rao (1977) and deposited at Gauhati University Botanical Herbarium (GUBH). The map depicting the location of Ruellia elegans collected from Tinsukia District of Assam has been shown (Figure 1).

 

Taxonomic Treatment

Ruellia elegans Poir. in J.B.A.M.de Lamarck, Encycl., Suppl. 4: 727.1816.   – Ruellia formosa Andrews in Bot. Repos. 10:t.610.1810. nom. illeg. – Ruellia superba D. Dietr. in Nachtr. Vollst. Lex. Gärtn. 17:307.1821.   –Arrhostoxylum formosum Nees in A.P. de Candolle, Prodr. 11:215.1847. – Arrhostoxylum roseum Nees in C.F.P. von Martius & auct. suc. (eds.), Fl. Bras. 9:61.1847.   – Arrhostoxylum silvaccola var. montanum Nees in C.F.P. von Martius & auct. suc. (eds.), Fl. Bras. 9:60.1847.     –Ruellia speciosa Mart. ex Nees in A.P.de Candolle, Prodr. 11: 215.1847. – Asystasia formosa T. Anderson in J. Agric. Soc. India, n.s., 1: 270.1868. – Stemonacanthus formosus T. Anderson in J. Agric. Soc. India, n.s., 1: 270.1868.  – Ruellia rosea (Nees) W. Bull in Nursery Cat. (William Bull) 143:8.1878. – Arrhostoxylum elegans (Poir.) Bremek. & Nann. Bremek. in Verh. Kon. Ned. Akad. Wetensch., Afd. Natuurk., Sect. 2, 45(1):12.1948.

 

Description

Annual erect herbs, 30–60 cm tall, ascending, sparsely branched, pubescent, quadrangular; Leaves 4–10 × 2–4 cm in size, acuminate, simple, entire, elliptic-oblong, coriaceous, cuneate base, sparsely pubescent adaxially, glabrous abaxially, exstipulate, petiole 1–2 cm long, flat, slender, pubescent; Inflorescence axillary, arising from upper leaves, raceme, 12–15 cm long, few flowered; Bract spathulate, pubescent, 0.8–1.2 × 0.4–0.6 cm; Flower pedicellate, bright red trumpet shaped, 4–5.5 cm long, bisexual, regular; Calyx 1.5–1.8 cm, five sepals, valvate, green, woolly, unequal lobes, united at base; Corolla with five petals, 1–1.5 cm segregated limbs above, lower part united to form 3–4 cm long floral tube, throat curved, pink-white patch inside, minutely hirsute outside, peduncle 0.5–1 cm long; Stamens 4, didynamous, 3.2–3.8 cm long, anthers white, 2.5–3 mm long, sub-extrorse, versatile, dithecous; Gynoecium 3.8–4 cm long, stigma bifid, pink, style pinkish white, ovary 2.8–3.7 mm, elliptic, glabrous, ovary disc 0.8–1 mm, cream-white. (Image 1)

Common names: Brazilian Petunia, Christmas pride, Elegant Ruellia, Red Ruellia, Wild Petunia.

Habitat: Terrestrial species found in high rainfall regions in wild or semi-wild patches/ margins of forest. Also, it grows well in understory of forests where partial sunlight falls.

Phenology: The flowering and fruiting has been observed during September.

 

Specimen examined

Brazil: South Brazil, Prov. St. Paul and Rio, Leg. Weir, J. 1861–62. #s.n. (K001048032! K001048033!); Environs de Rio de Janeiro et D´Ouro Preto, Leg. Moss A. Glaziou, v.1885. Coll.No.15297 (K001048034!); São Paulo, Leg. M. Kuhlman, 13.xi.1947. Coll.No.1518 (K001048038!); Minas Gerais, 20.3294°S, 46.3052°W, altitude 780 m, Leg. Souza, V.C. 14.i.1994. Coll.No.5059 (K001048037!); Near Rio, Leg. Graham. #s.n. (K001048035!) Determined by C. Kameyama, 1995; São Paulo, Leg. M. Groppo Jr. 26.ii.2001. Coll.No.595 (K001048036!). India: Andaman & Nicobar Islands, Port Blair, Nayagaon, South Andamans, Dr. S. Kumar, 15.iii.2008. Coll.No.26343 (PBL0000015227! PBL0000015228!). Assam: Tinsukia, Digboi, Near Dehing Patkai WS, Mamita Kalita, 19.ix.2023. Coll.No. TSRE03 (GUBH20634).

 

Taxonomic note

The specific epithet `elegans´ propound the pleasing appearance or bounteous nature of the species.  The herbarium specimen (K001048032, K001048033, K001048038) were initially identified as Ruellia formosa and (K001048032, K001048033, K001048034, K001048035) as Arrhostoxylum formosum. Later, the correct identification was provided as Ruellia elegans and the former two names are now treated as synonyms. A write up over the herbarium sheet K001048035 describe the species as plants with bright red flowers having four anthers (two long and two short ones). As mentioned by Ezcurra (1993), the calyx and corolla morphology of R. elegans is somewhat similar to R. sceptrum-marianum (Vell.) Stearn., and R. acutangula Nees, R. silvaccola (Nees) Lindau. Further, he described the species as red flowers having horizontal corolla forming a narrow tube with weak peduncles and pedicels. The presently examined species have similar floral attributes as described.

 

Conclusion

At the location site, altogether 8–10 individuals of the plant species were seen, each differing in their reproductive growth. Few other species growing along with Ruellia elegans are: Diplazium sp., Dryopteris sp., Isodon sp., Oxalis debilis, Plantago major, and Rostellularia sp. According to Rao & Kumar (2024), the species conservation status is not assessed in Brazil. The impacts of this invasive species should be monitored to take appropriate measures to control its spread threatening the native biodiversity.

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References

 

Ezcurra, C. (1993). Systematics of Ruellia (Acanthaceae) in Southern South America. Annals of the Missouri Botanical Garden 80(4): 787–845. https://doi.org/10.2307/2399931

Jain, S.K. & R.R. Rao (1977). Handbook of Field and Herbarium Methods. Today and Tomorrow Printers and Publishers, New Delhi, India, 150 pp.

Kalidass, C., P. Murugan & P.C. Panda (2016). Ruellia elegans Poir. (Acanthaceae): A new plant record for Eastern India. Plant Science Research 38(1&2): 118–119.

Lamarck, J.B. & J.L.M. Poiret (1816). Encyclopédie méthodique. Botanique, Supplement. Paris, Agasse. 4:  727 pp. https://doi.org/10.5962/bhl.title.826

Manzitto-Tripp, E.A., I. Darbyshire, T.F. Daniel, C.A. Kiel & L.A. McDade (2021). Revised classification of Acanthaceae and worldwide dichotomous keys. TAXON 71(5): 103–153. https://doi.org/10.1002/tax.12600

POWO (2024). Facilitated by the Royal Botanic Gardens, Kew. Published on the Internet. Accessed on 25/09/2023. https://powo.science.kew.org/

Rao, K.S. & D. Kumar (2024). India Flora Online. Published on the Internet; https://indiaflora-ces.iisc.ac.in/

Stevens, P.F. (2001 onwards). APG IV. Angiosperm Phylogeny Website. Version14, July 2017. http://www.mobot.org/MOBOT/research/APweb/

Tripp, E.A. (2007).  Evolutionary relationships within the species-rich genus Ruellia (Acanthaceae). Systematic Botany 32(3):628–649. https://doi.org/10.1600/036364407782250625

Tripp, E.A., T.F. Daniel, S. Fatimah & L.A. McDade (2013). Phylogenetic Relationships within Ruellieae (Acanthaceae) and a Revised Classification. International Journal of Plant Sciences 174(1): 97–137. https://doi.org/10.1086/668248

Zhuang, Y. & E.A. Manzitto-Tripp (2022). Co-expression network analyses of anthocyanin biosynthesis genes in Ruellia (Wild Petunias; Acanthaceae). BMC Ecology and Evolution 22(27): 1–17. https://doi.org/10.1186/s12862-021-01955-x