INTRODUCTION
⌅Kalanchoe Adans. (Crassulaceae) sensu lato includes about 150 species worldwide, with its centre of diversity in Madagascar (Smith & Figueiredo 2018Smith G.F. & Figueiredo E. 2018. The infrageneric classification and nomenclature of Kalanchoe Adans. (Crassulaceae), with special reference to the southern African species. Bradleya 36: 162-172., 2019Smith G.F. & Figueiredo E. 2019. A new status and combination in a Madagascan Kalanchoe, K. beauverdii var. juelii (Crassulaceae subfam. Kalanchooideae). Phytotaxa 414: 119-120. ). Kalanchoe is the fourth species-rich genus in Crassulaceae after Sedum L. (463 spp.), Crassula L. (205 spp.), and Echeveria DC. (197 spp.) (POWO 2022POWO 2022. Plants of the World Online. Facilitated by the Royal Botanic Gardens, Kew. Published on the Internet; http://www.plantsoftheworldonline.org/ [accessed: 20 Jun. 2022].).
Hamet (1907)Hamet R. 1907. Monographie du genre Kalanchoe. Bulletin de l’HerbierBoissier Sér. 2, 7: 869-900. treated Kalanchoe, Bulbophyllum Thouars, and Kitchingia Baker as a single genus, while Boiteau (1947)Boiteau P. 1947. Les plantes grasses de Madagascar. Cactus 12: 5-10. proposed to divide Kalanchoe into three sections: Kalanchoe sect. Eukalanchoe, K. sect. Kitchingia (Baker) Boiteau, and K. sect. Bryophyllum (Salisb.) Boiteau. POWO (2022)POWO 2022. Plants of the World Online. Facilitated by the Royal Botanic Gardens, Kew. Published on the Internet; http://www.plantsoftheworldonline.org/ [accessed: 20 Jun. 2022]. included 160 species in Kalanchoe, with its native range in tropical and subtropical Old World. The most recent species level treatment of Kalanchoe was published by Descoings (2003Descoings B. 2003. Kalanchoe. In Eggli U. (ed.). Illustrated handbook of succulent plants: Crassulaceae. Springer-Verlag, Berlin, Heidelberg New York., 2006Descoings B. 2006. Le genre Kalanchoe structure et définition. Journal de Botanique de la Société Botanique de France 33: 3-28.) who provided an infrageneric classification for Kalanchoe, recognizing three subgenera: Kalanchoe subgen. Kalanchoe, K. subgen. Bulbophyllum (Salisb.) Koorders, and K. subgen. Calophygia Descoings. Smith & Figueiredo (2018)Smith G.F. & Figueiredo E. 2018. The infrageneric classification and nomenclature of Kalanchoe Adans. (Crassulaceae), with special reference to the southern African species. Bradleya 36: 162-172. also recognized three subgenera, but replacing the subgen. Calophygia by K. subgen. Kitchingia (Baker) Gideon F.Sm. & Fiqueiredo.
Clarke (1878)Clarke C.B. 1878. Kalanchoe. In Hooker J.D. (ed.) Flora of British India vol. 2. L. Reeve & Co., London. pp. 414-416. reported six species of Kalanchoe in the Flora of British India, while Singh & al. (2011)Singh N.B., Bhattacharyya U.C. & Uniyal B.P. 2011. Crassulaceae of India. Bishen Singh Mahendrapal Singh, Dehradun. included nine species from India. Gamble (1919)Gamble J.S. 1919. Crassulaceae. The Flora of Presidency of Madras vol. 1. Adlard and Son Ltd., London. recorded six species in Flora of Presidency of Madras, which include two endemic species: K. olivacea Dalzell and K. bhidei T.Cooke, which were not discussed by Clarke (1878)Clarke C.B. 1878. Kalanchoe. In Hooker J.D. (ed.) Flora of British India vol. 2. L. Reeve & Co., London. pp. 414-416.. Nandikar & al. (2019)Nandikar M.D., Rohini A., Shinde & Noltie H.J. 2019. Taxonomy and typification of Kalanchoe olivacea and K. bhidei (Crassulaceae). Rheedea 29: 197-208. provided a detailed analysis of the above species, including their typification. Scientific surveys between 2014 and 2018, as a part of documenting the flowering plant diversity of Mathikettan Shola National Park, resulted in collecting a few specimens of Kalanchoe. Detailed studies in consultation with type/protologue of the related species and relevant literature (Wight 1846Wight R. 1846. Crassulaceae. Icones Plantarum Indiae Orientalis vol. 3. J.B. Pharoah, Madras, t. 1158.; Cooke 1903Cooke T. 1903. Flora of the Presidency of Bombay vol. 1. Taylor and Francis, London.; Hamet 1907Hamet R. 1907. Monographie du genre Kalanchoe. Bulletin de l’HerbierBoissier Sér. 2, 7: 869-900. ; Gamble 1919Gamble J.S. 1919. Crassulaceae. The Flora of Presidency of Madras vol. 1. Adlard and Son Ltd., London.; Boiteau 1947Boiteau P. 1947. Les plantes grasses de Madagascar. Cactus 12: 5-10.; Gandhi 1976Gandhi K.N. 1976. Kalanchoe. In Saldanha C.J. & Nicolson D.H. (eds.). Flora of Hassan district, Karnataka, India. Amerind Publishing Co. Pvt. Ltd., New Delhi. pp. 207-10.; Srinivasan 1983Srinivasan S.R. 1983. Crassulaceae. In Nair N.C. & Henry A.N. (eds.), Flora of Tamil Nadu, India: Analysis vol.1. Botanical Survey of India. Coimbatore. ; Deshpande & Sharma 1984Deshpande S. & Sharma B.D. 1984. A note of the topotypic occurrence of Kalanchoe bhidei Cooke (Crassulaceae) after eight decades. Bulletin of Botanical Survey of India 26 (3-4): 238-239. ; Rao 1984Rao R.R. 1984. Crassulaceae In Saldanha C.J. (ed.), Flora of Karnataka vol.1. Oxford & IBH Publishing Co., New Delhi.; Sharma & al. 1984Sharma B.D., Singh N.P., Raghavan R.S. & Deshpande U.R. 1984. Flora of Karnataka. Analysis. Flora of India Series. Botanical Survey of India, Kolkata. ; Godbole & Das 2000Godbole A. & Das S.K. 2000. Crassulaceae. In Singh N.P. & Karthikeyan S. (eds.), Flora of Maharashtra vol. 1. Botanical Survey of India, Kolkata.; Descoings 2003Descoings B. 2003. Kalanchoe. In Eggli U. (ed.). Illustrated handbook of succulent plants: Crassulaceae. Springer-Verlag, Berlin, Heidelberg New York., 2006Descoings B. 2006. Le genre Kalanchoe structure et définition. Journal de Botanique de la Société Botanique de France 33: 3-28.; Chernetskyy 2011Chernetskyy M. 2011. Problems in nomenclature and systematics in the subfamily Kalanchoideae (Crassulaceae) over the years. Acta Agrobotanica 64: 67-74.; Singh & al. 2011Singh N.B., Bhattacharyya U.C. & Uniyal B.P. 2011. Crassulaceae of India. Bishen Singh Mahendrapal Singh, Dehradun.; Sasidharan 2012Sasidharan N. 2012. Flowering Plants of Kerala, version 2. Kerala Forest Research Institute, Peechi.; Chorghe & al. 2017Chorghe A.R., Rasingam L., Prasanna P.V. & Sankara Rao M. 2017. Three new additions to the flora of Eastern Ghats. Nelumbo 59: 66-70. ; Smith & Figueiredo 2018Smith G.F. & Figueiredo E. 2018. The infrageneric classification and nomenclature of Kalanchoe Adans. (Crassulaceae), with special reference to the southern African species. Bradleya 36: 162-172., 2019Smith G.F. & Figueiredo E. 2019. A new status and combination in a Madagascan Kalanchoe, K. beauverdii var. juelii (Crassulaceae subfam. Kalanchooideae). Phytotaxa 414: 119-120. ; Nandikar & al. 2019Nandikar M.D., Rohini A., Shinde & Noltie H.J. 2019. Taxonomy and typification of Kalanchoe olivacea and K. bhidei (Crassulaceae). Rheedea 29: 197-208.) revealed that the collected specimens represent a hitherto undescribed species, which is established here as new to science.
MATERIALS AND METHODS
⌅More than 20 specimens that represented a new taxon were collected from four adjoining populations in Mathikettan Shola National Park. The flowers were pickled in 4% formalin and 70% ethanol for further study. The herbarium specimens were prepared by conventional methods (Bridson & Forman 1991Bridson D.M. & Forman L. 1991. The Herbarium Handbook. Royal Botanic Gardens, Kew.). The description was prepared after examining all available specimens of the new taxon. The specimens of related taxa in CALI herbarium, and digital images of types of other Kalanchoe species at K and P herbaria were also examined. The conservation status of the new species was assessed as per IUCN Red List Categories and Criteria (IUCN 2022IUCN 2022. Guidelines for using the IUCN Red list Categories and Criteria. Version 15. Prepared by the Standards and Petitions Subcommittee of the IUCN Species Survival Commission. https://www.iucnredlist.org/resources/redlistguidelines [accessed: 20 Jun. 2022].). Photographs of habitat and habit were taken with an α A55 DSLR camera (Sony, Japan) and floral details with a Stemi 508 stereo microscope (Zeiss, Germany) outfitted with an Axiocam 105 color camera (Zeiss). Illustrations were drawn by camera lucida attached to a Stemi 508 stereomicroscope.
RESULT AND DISCUSSION
⌅Taxonomic treatment
⌅Kalanchoe dineshii Syam Radh & Nampy, sp. nov. Type: India, Kerala: Idukki district, Mathikettan Shola National Park, Near Aduvizhunthankudi, c. 1590 m, 22 Nov. 2014, S.S. Radh & S. Nampy 137816 (holotype: CALI!; isotype CAL!).Figs. 1 & 2.
Diagnosis.-Kalanchoe dineshii is morphologically close to K. bhidei but can be easily distinguished from the latter by its smaller size (up to 40 vs. up to 100 cm tall in K. bhidei), sessile obovate to obtrullate leaves (vs. petiolate ovate to elliptic or oblanceolate), smaller bracts (1.5 vs. 5 mm long), and widely ovate calyx lobes (vs. narrowly ovate or trigonous).
Description.-Erect to decumbent, perennial, succulent herbs, 30-40 cm tall, glabrous, reddish white throughout. Stems woody at base, glabrous, with prominent leaf scars on lower part. Leaves sessile, basal 1/4th adnate to the stem; lamina obovate to obtrullate, 3-4.5 × 2-2.5 cm, obtuse to rounded at apex, both surfaces glabrous, margins undulate to incised at distal half, entire at basal half; veins pinnate-netted, lateral veins obscure. Inflorescences terminal, trichotomous corymbs, not spreading; peduncles 6-8 cm long, glabrous; involucral bracts leafy, obtrullate, 2.5-3 × 1.5-2 cm, margins incised, reddish white; pedicels 3-5 mm long, glabrous. Bracts lanceolate, 1.5 × 0.5 mm, glabrous. Flowers hermaphrodite, 9-13 × 4-6 mm, glabrous, closely packed. Calyx lobes 4, basally fused, widely ovate, pale green, 2-3 × 1.5-2 mm, glabrous, persistent in fruit. Corolla tube 4-angular, bulged at base, 8-1 × 2 mm, fleshy, glabrous; lobes 4, 3-5 × 2-3 mm, widely ovate, wavy at margins, caudate at apex, pinkish-white, glabrous. Stamens 8, outer whorl arising from the base of corolla lobes and inner whorl from the middle of corolla tube; filaments unequal, 1-2 mm long, glabrous, white; anthers 0.75 × 0.75 mm, elliptic, basifixed, yellow, dehiscing longitudinally. Nectar scales 4, subulate, adnate to each carpel, 2.5-3 mm long, glabrous. Carpels 4, bottle shaped, free; ovary 3 × 1 mm, glabrous; ovules numerous; style 3-5 mm long, cylindrical, glabrous; stigma capitate. Follicles 6 × 3 mm, glabrous; seeds many.
Phenology.-Kalanchoe dineshii was collected with flowers and fruits during November to January.
Distribution and habitat.-The new species is only known from four adjoining populations in the type locality, Mathikettan Shola National Park in Idukki district of Kerala; on rocks in grasslands, between 1550-1600 m elevation. It is associated, among other species, with Cyanotis arachnoidea C.B.Clarke (Commelinaceae), Tripogon bromoides Roth ex Roem. & Schult. (Poaceae).
Provisional conservation status.-The total area of Mathikettan Shola National Park is 12.81 km2. The area was earlier exposed to severe anthropogenic activities, which caused serious habitat destruction. However, considering the unique nature of the shola forests and its importance as an elephant corridor, the area was declared as a National Park in 2003. The new taxon was collected in one location in the park from four adjoining populations. The lack of number of locations precludes estimation of Extent of Occurrence. The Area of Occupancy is below 10 km2 and the number of mature individuals recorded was 20. There are cardamom and coffee plantations adjoining to the National Park, where human activities are frequent. Since the area belongs to a national park, current threats are minimal. Despite this, the species is provisionally classified here as Critically Endangered (CR, D), based on restricted populations and number of mature individuals.
Etymology.-The epithet ‘dineshii’ honours Dr. Dinesh Raj (Assistant Professor, Department of Botany & Biotechnology, Bishop Moore College, Mavelikkara), who introduced the first author to the field of angiosperm taxonomy.
Notes.-Apart from sexual reproduction, some Kalanchoe species show pronounced asexual reproductive strategies (Smith & al. 2022Smith G.F., Shtein R., Klein D.-P., Parihar B., Almeida A., Rodewald S., Kadereit G. 2022. Sexual and asexual reproduction inKalanchoe(Crassulaceae): A review of known and newly recorded strategies. Haseltonia 28: 2-20.), but this feature is not found in K. dineshii. Several populations of this new species were observed continuously in the natural habitat for three years and it was showed that the diagnostic characters remain unchanged. Kalanchoe dineshii appears to be most closely related to K. bhidei and K. olivacea (Table 1).
| Characters | K. dineshii | K. bhidei | K. olivacea |
|---|---|---|---|
| Height (cm) | 30-40 | 30-100 | 15-63 |
| Leaves | Obovate to obtrullate, 3-4.5 × 2-2.5 cm, margins undulate to incised at distal half, entire at basal half | Ovate to elliptic or oblanceolate, 2-12 × 2-5 cm, margins crenate, distal leaves dentate to entire | Ovate to lanceolate or oblanceolate, 1-10 × 0.5-4 cm, margins usually crenate, distal leaves crenate to dentate to entire |
| Petioles | Absent | Subsessile | Subsessile |
| Inflorescence | Not spreading | Widely spreading | Not spreading |
| Bracts | 1.5 mm long, glabrous | ca. 5 mm long, glabrous | c. 2 mm long, glandular hairy |
| Pedicels | 3-5 mm long, glabrous | 3-7 mm long, glabrous | 5-7-(10) mm long, glandular hairy |
| Calyx lobes | Widely ovate, 2-3 mm long, glabrous | Narrowly ovate or trigonous, c. 4 mm long, glabrous | Lanceolate, 4.7-6.4 mm long, densely glandular hairy |
| Corolla | Tube glabrous; lobes widely ovate, apex caudate, glabrous | Tube glabrous; lobes white, narrowly ovate to lanceolate, apex acute to acuminate, glabrous | Tube glandular hairy out, lobes white, lanceolate, apex acuminate to caudate, densely to sparsely glandular hairy out |
| Anthers | Elliptic | Ellipsoid | Ellipsoid |
| Nectar scale | Subulate | Linear to ensiform | Linear |
Additional specimens studied.-INDIA. Kerala: Idukki district, Mathikettan Shola National Park, Choondal, ± 1550 m, 4 Nov. 2015, S.S. Radh & K.M. Manudev 145081 (CALI); way to Perattakkalam, ± 1590 m, 4 Jan. 2017, S.S. Radh & D. Francis 151529 (CALI); way to Sivanpara check post, ± 1600 m, 3 Dec. 2018, S.S. Radh & T.K. Sreekutty 151789 (CALI).