257 Amaranthus powellii (Amaranthaceae), a new addition for the flora of India and a preliminary list of the Indian Amaranthus species Abstract Three populations of Amaranthus powellii were discovered in Kerala region (SE-India), representing the first record of this species for the national flora. A morphological description based on the Indian plants, as well as ecological data are given. A preliminary list of all the Amaranthus species occurring in India, which was never published during the last 136 years, is also provided. Iz vleček V regiji Kerala (JI-Indija) smo odkrili tri populacije vrste Amaranthus powellii, ki predstavljajo prvo najdbo te vrste v flori Indije. Na osnovi primerkov iz Indije smo podali morfološki opis in ekološke podatke. Sestavili smo tudi seznam vseh vrst rodu Amaranthus z območja Indije, ki je ponovno objavljen po 136 letih. Key words: Alien species, Amaranthus species list, Asia, new record. Ključne besede: tujerodne vrste, seznam vrst rodu Amaranthus, Azija, nove najdbe. Received: 28. 8. 2020 Revision received: 5. 1. 2021 Accepted: 5. 1. 2021 1 Department of Botany, Research centre University of Kerala, University College, Thiruvananthapuram, 695034-Kerala, India. 2 Department of Botany, University of Pisa, Via Luca Ghini 13, 56126-Pisa, Italy. 3 Department of Botany, Government College, Vidhya Nagar, Kasaragod, 671123-Kerala, India. * Corresponding author. E-Mail: d.iamonico@yahoo.it Sindhu Arya1  , Duilio Iamonico2 , *  & Venugopalan Nair Saradamma Anil Kumar3  DOI: 10.2478/hacq-2021-0005 20/2 • 2021, 257–262 20/2 • 2021, 257–262 258 Sindhu Arya, Duilio Iamonico & Venugopalan Nair Saradamma Anil Kumar Amaranthus powellii (Amaranthaceae), a new addition for the flora of India and a preliminary list of the Indian Amaranthus species Introduction The genus Amaranthus L. (Amaranthaceae Juss.) includes 65–70 species of which approximately half are native to the Americas (see Mosyakin & Robertson 1996, Iamo- nico 2015a). Some species are used as ornamentals, food or medicine and are able to escape from cultivation, nega- tively impacting the agricultural systems and/or the natu- ral vegetation (see Iamonico 2010, 2015a, Das 2016). Amaranthus is a taxonomically critical genus, due to its high phenotypic variability which has resulted in the current nomenclatural confusion and misapplication of several names (see e.g., Costea et al. 2001, Bayón 2015, Iamonico 2016a, 2016b, 2016c, 2020a, 2020b, 2020c Iamonico & Palmer 2020). As part of an ongoing investigation on the Indian spe- cies of Amaranthus (Iamonico & Das 2014, Arya et al. 2019, Sindhu et al. 2020), we found some populations of Amaranthus powellii S. Watson, a species never recorded for the national flora. Morphological notes, as well as eco- logical data are presented here. A preliminary list of all the Amaranthus species occurring in India, which were never published since 136 years, is also provided. Materials and methods The research is based on field surveys [collected specimens are deposited at CALI, HFLA, and TBGT], analysis of relevant literature, and examination of specimens pre- served at AO, APP , FI, HFLA, G, GH, K, KFRI, MH, NY, RO, and TSB (herbarium codes follow Thiers 2021 [continuously updated]). The description of the species is based on the plants observed in field. Results and discussion First record for Indian flora Amaranthus powellii, a species originally described by Watson (1875: 347) from Arizona, is native to North America and Mexico (see e.g., Mosyakin & Robert- son 2003), whereas it was considered as alien in North and Central Africa [Morocco and Algeria (see Iamonico 2015b, SANBI 2012), Ethiopia, Uganda, and Tanzania (see Costea et al. 2001)], Asia [Pakistan (see Costea et al. 2001), and Korea (Park et al. 2014)], Australia (Palmer 2009), and Europe (Iamonico 2015b). Three populations of Amaranthus powellii were found in South India, Kerala State, Kasaragod District, in Chen- gala suburb (localities Naimarmoola and 4 th Miles) and Mulleria town (Figure 1), at elevation 54–173 m a.s.l. The first observation of Amaranthus powellii was in 2018 and the populations found still occur in the above men- tioned sites. A total of 27–35 individuals were counted in these sites occupying an area of about 3 m 2 per site. We observed the flowering and fruiting times from June to February. On the basis of literature (see the above men- tioned citations and the paragraph 3.2 below), these pop- ulations represent the first record of this species for the Flora of India (see also POWO 2020-onward). Since the recent observation (2018) and the low num- ber of individuals found (27–35), although the popula- tion seems fertile, we consider Amaranthus powellii as a casual alien species for India according to Pyšek et al. (2002). However, future monitoring will be carried out to check the possible naturalization of the species. Amaranthus powellii S.Watson., Proc. Amer. Acad. Arts 10: 347. 1875 ≡ Amaranthus chlorostachys var. powel- lii (S.Watson) Priszter, Agrártud. Egyet. Kert- Szölögaz- daságtud. Karának Évk. 2: 144. 1953 ≡ Amaranthus hy- bridus subsp. powellii (S.Watson) Karlsson, Nord. J. Bot. 20: 519. 2000 ≡ Amaranthus hypochondriacus var. powellii (S.Watson) Pedersen, Monogr. Syst. Bot. Missouri Bot. Gard. 74: 1245. 1999 ≡ Amaranthus retroflexus var. powel- lii (S.Watson) B.Boivin, Naturaliste Canad. 93(5): 641. 1966 – Lectotype (designated by Iamonico 2015: 157): USA, Arizona, “from Powell’s Arizona seeds”, 1874, Pow- ell s.n. (US00106256!). Image of the lectotype available Figure 1: Amaranthus powellii in India (photos by A. Sindhu). Slika 1: Amaranthus powellii v Indiji (fotografije A. Sindhu). 20/2 • 2021, 257–262 259 Sindhu Arya, Duilio Iamonico & Venugopalan Nair Saradamma Anil Kumar Amaranthus powellii (Amaranthaceae), a new addition for the flora of India and a preliminary list of the Indian Amaranthus species at http://n2t.net/ark:/65665/m3d80bd736-5d12-4c99- a23a-1383db663680 Description: annual herb (therophyte), monoecious, 200–250 cm tall. Stem erect, reddish, glabrous (pu- bescent in the synflorescence region), ribbed, branched at the proximal half. Leaves simple, alternate, ovate- rhombic (10.5–14.5 × 4.5–9.5 cm), green, with entire margin, apex usually slightly emarginated, mucronate, base cuneate, glabrous, petioled (petiole pubescent, 12–14 cm long). Synflorescence terminal, panicle-like, few branched, the main florescence 28–30 × 2–3 cm, the paraclades 15–16 × 1.5–2.0 cm. Bracts lanceolate- subulate (7.0–8.5 mm long), 2.8–5.5 times longer than the perianth, green, glabrous, awned, with membranous borders narrowing to apex. Staminate flowers occurring throughout the synflorescences, with 5 unequal tepals, lanceolate-oblanceolate (2.5–3.4 mm long), mucronate; stamens (4–)5; anthers sagittate. Pistillate flowers oc- curring throughout the synflorescence, with 5 unequal tepals, lanceolate-linear (3.1–4.2 mm long), with acute and mucronate apex; gynoecium green, ovary 1-celled, 1 ovule, glabrous; stigmas 2–3. Fruit brown, ovoid (1.3– 1.8 × 0.8–1.2 mm), shorter than the perianth, dehiscent. Seed lenticular (0.5 × 0.6 mm in diameter), black to red- dish-brown. Phenology: Flowering and fruiting times June–February . Habitat, distribution, and status of naturalization in India: Amaranthus powellii occurs in waste lands in three sites of Kasaragod District (Kerala State) at Chengala sub- urb [localities Naimarmoola (54 m a.s.l.) and 4 th Miles (83 m)] and Mulleria town (173 m). This species is cur- rently considered as casual alien. Chorology: native to North America and Mexico (see e.g., Mosyakin & Robertson 2003). Some authors (e.g., Iamonico 2015a or Costea et al. 2001) considered Ama- ranthus powellii as native to North and South America. Taxonomic notes: On the basis of the personal obser- vation on hundreds of plants (by DI) and literature data, the Indian plants differ from the typical Amaranthus powellii by plant size and by the length of the bract of pistillate flowers. Concerning the height of plant, Indian plants of A. powellii are over than 2 m tall, while this species is usually up to 1.5 m high (see e.g., Mosyakin & Robertson 2003, Iamonico 2015a). However, it is well known that this feature does not have a taxonomic value in Amaranthus and it depends from ecological factors, such as light, available nitrate in soil, trampling, etc. (see e.g., Iamonico 2010, Costea et al. 2004). On the other hand, the length of the bracts is a character commonly used to identify taxa in Amaranthus and especially in the A. hybridus group, where A. powellii belongs (see e.g., Iamonico 2015a). Individuals of A. powellii found in India display bracts 7.0–8.5 mm long, whereas this spe- cies shows bracts up to 7 mm long (see e.g., Mosyakin & Robertson 2003, Iamonico 2015a). The ratio bract/peri- anth (also a good taxonomic character in Amaranthus) is about 2.8–5.5 in the Indian plants, whereas it is 2.0–3.7 in A. powellii. Specimina Visa Selecta: INDIA. Naimarmoola Kasaragod (north east), small population in the market road, 12°51’52’’ N,75°02’27”E, 54 m a.s.l, 10.X.2019, V S Anilkumar s.n. (CALI). 4th Mile (Kasaragod, South), scattered populations, 12°51’07” N, 75°03’79” E, 83 m a.s.l., 20.IX.2019, V S Anilkumar s.n. (TBGT). Mulle- ria (Kasaragod, North), along road sides and wastelands, 12°54’87” N, 75°16’52” E, 173 m a.s.l., 20.II.2020, V S Anilkumar s.n. (TBGT). List of Amaranthus species occurring in India At the current state of knowledge, no list of the species belonging to the genus Amaranthus has been published for the whole India since 1885, when Hooker (1885: 718–722), in the volume no. 4 of his Flora of British In- dia, recognized 10 species plus three further “doubtful species”. However, according to the current species con- cept in Amaranthus, only 8 species can be accepted (see Table 1 and literature therein cited). Before Hooker (1885), a complete taxonomic treat- ment of Amaranthus for India was published by Rox- burgh (1832) in the 3 rd volume of his Flora Indica where 18 species was recognized, but they currently refer to 6 species and 7 taxa (see Table 2 and and literature therein cited). During the XX century, no taxonomic revision of Am- aranthus was published for the India subcontinent, and we were able to trace just one taxonomic paper by Thakur (1967), who clarified the identity of the name “ Amaran- thus caturus Heyne” reaching to the conclusion that it refers to a hybrid between A. tricolor L. and A. viridis L. Concerning XXI century, several new taxa were pub- lished by Das (2013), who described a new variety of A. tricolor L. (var. acutus Sabuhik Das), Das (2014, A. par- ganensis Sabuhik Das), Iamonico & Das [2014, A. benga- lensis Iamonico & Sabuhik Das (as “bengalense”)], Arya et al. (2019, A. saradhiana Arya et al.), and Sindhu et al. (2020, A. rajasekharii Sindhu et al.). Note that Das (2014) also reported from West Bengal A. dubius Mart. ex Thell. and A. hybridus L. Currently, 19 taxa of Amaranthus (17 species) occur in India (Table 3), and this represents the first preliminary list of Indian amaranths published since 136 years. 20/2 • 2021, 257–262 260 Sindhu Arya, Duilio Iamonico & Venugopalan Nair Saradamma Anil Kumar Amaranthus powellii (Amaranthaceae), a new addition for the flora of India and a preliminary list of the Indian Amaranthus species Table 1: List of recognized species by Hooker (1885: 718–722) as reported in the vol. 4 of Flora of British India [doubful species by Hooker (1885) are marked with an asterisk, *] and names currently accepted (if accepted names are different from the Linnaean ones, a reference is reported). Tabela 1: Seznam vrst, ki jih je navedel Hooker (1885: 718–722) v četrtem delu Flora of British India [dvomljive vrste po Hooker (1885) so označene z zvezdico, *] in trenutno veljavna imena (če se veljavno ime razlikuje od Linnejevskih je neveden vir). Recognized species by Hooker (1885) Currently accepted names Amaranthus spinosus L. Amaranthus spinosus L. Amaranthus paniculatus L. Amaranthus cruentus L. (Iamonico 2015: 55) Amaranthus caudatus L. Amaranthus caudatus L. Amaranthus gangeticus L. Nomen Incertae Sedis (Iamonico 2014a) Amaranthus mangostanus L. Amaranthus tricolor L. (Iamonico 2014b: 147) Amaranthus caturus Heyne Amaranthus × caturus Heyne ex Hook.f. (Thakur 1967) Amaranthus viridis L. Amaranthus viridis L. Amaranthus blitum L. Amaranthus blitum L. s.str. (Iamonico 2015a: 27) Amaranthus polygamus L. Amaranthus tricolor L. (Iamonico 2014b: 148) Amaranthus tenuifolius Willd. Amaranthus graecizans L. s.str. (Iamonico 2020b: 152) Amaranthus atropurpureus Roxb.* Amaranthus tricolor L. (Iamonico 2020c: 563). Amaranthus campestris Willd.* Amaranthus albus L. (Iamonico 2020b: 149) “Amaranthus rubricaulis Page”, nom. nud.* Arts. 38.1 and 38.2 (T urland et al. 2018); see Iamonico (2016c: 89) T able 2: List of recognized species by Roxburgh (1832: 601–611) as reported in the vol. 3 of Flora Indica and names currently accepted. Tabela 2: Seznam vrst, ki jih je navedel Roxburgh (1832: 601–611) v tretjem delu Flora Indica in trenutno veljavna imena. Recognized species by Roxburgh (1832) Accepted names Amaranthus tenuifolius Willd. Amaranthus graecizans L. s.str. (Iamonico 2020b: 152) Amaranthus polygonoides Willd. Amaranthus polygonoides L. (Iamonico 2015a: 43) Amaranthus polygamus Willd. Amaranthus tricolor L. (Iamonico 2014b: 148) Amaranthus tristis Willd. Amaranthus tricolor L. (Iamonico 2014b: 144) Amaranthus viridis Willd. Amaranthus viridis L. (Iamonico 2015a: 22) Amaranthus lividus Willd. Amaranthus blitum L. s.str. (Iamonico 2015a: 27) Amaranthus oleraceus Willd. Amaranthus blitum L. var. oleraceus (L) Hook.f. (Iamonico 2015a: 29) Amaranthus gangeticus Willd. Nomen Incertae Sedis (Iamonico 2014a) Amaranthus lanceolatus Roxb. Amaranthus tricolor L. (Iamonico 2020c: 564). Amaranthus atropurpureus Roxb. Amaranthus tricolor L. (Iamonico 2020c: 563). Amaranthus tricolor Willd. Amaranthus tricolor L. Amaranthus melancholicus Willd. Amaranthus tricolor L. (Iamonico 2015a: 24) Amaranthus fascicatus Roxb. Amaranthus blitum L. s.str. (Iamonico, submitted 6 ). Amaranthus albus L. Amaranthus bengalensis Iamonico & Sabuhik Das Amaranthus blitum L. subsp. blitum var. blitum Amaranthus blitum L. subsp. blitum var. oleraceus (L.) Hook. f. Amaranthus × caturus Heyne ex Hook. f. Amaranthus cruentus L. Amaranthus caudatus L. Amaranthus dubius Mart. ex Thell. Amaranthus graecizans L. subsp. graecizans Amaranthus hybridus L. Amaranthus parganensis Sabuhik Das Amaranthus polygonoides L. Amaranthus powellii S.Watson Amaranthus rajasekharii S.Arya, V.S.A. Kumar, W.K.Vishnu & Iamonico Amaranthus saradhiana S.Arya, V .S.A. Kumar, W .K.Vishnu & Rajesh Kumar Amaranthus spinosus L. Amaranthus tricolor L. var. acutus Sabuhik Das Amaranthus tricolor L. var. tricolor Amaranthus viridis L. Table 3: Preliminary list of the species of Amaranthus occurring in India. Names are given in alphabetical order. Tabela 3: Preliminarni seznam vrst rodu Amaranthus, ki se pojavljajo v Indiji. Imena so navedena po abecednem redu. 20/2 • 2021, 257–262 261 Sindhu Arya, Duilio Iamonico & Venugopalan Nair Saradamma Anil Kumar Amaranthus powellii (Amaranthaceae), a new addition for the flora of India and a preliminary list of the Indian Amaranthus species Acknowledgements Thanks are due to Directors and Curators of all the quot- ed herbaria for their support. 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