Achyranthes aspera L.

Sukhorukov, Alexander P., Kushunina, Maria, Nilova, Maya V., Baider, Cláudia & Sennikov, Alexander N., 2024, Africa and Arabia encompass a much greater species diversity in the Achyranthes aspera aggregate (Amaranthaceae, achyranthoid clade): Evidence from morphological and chorological data, PhytoKeys 250, pp. 21-94 : 21-94

Achyranthes aspera L. , Sp. Pl. 1: 204 (1753) nom. cons.

≡ Achyranthes aspera var. indica L. Sp. Pl. 1: 204 (1753).

≡ Achyranthes indica (L.) Mill. , Gard. Dict., ed. 8: [unpaged] Achyranthes no. 2 (1768).

≡ Cadelaria indica (L.) Raf. , Fl. Tellur. 3: 45 (1837).

≡ Stachyarpagophora aspera (L.) M. Gómez , Anales Inst. Segunda Enseñ. 2: 312 (1896).

≡ Centrostachys aspera (L.) Standl., J. Wash. Acad. Sci. 5: 75 (1915) .

≡ Centrostachys indica (L.) Standl., J. Wash. Acad. Sci. 5: 75 (1915) .

= Achyranthes obtusifolia Lam. , Encycl. 1 (2): 545 (1785).

≡ Achyranthes aspera var. obtusifolia (Lam.) Suess. , Mitt. Bot. Staatssamml. München 1 (5): 152 (1952). Lectotype (designated here): [ India?] leg. Sonnerat s. n. (P-LA 00380993, image!).

= Achyranthes argentea var. obovata Moq. in DC., Prodr. 13 (2): 316 (1849). Holotype: [ Saudi Arabia] “ Locis cultis ad pagum Madara vallis Fatme prope Meccam ”, 24 November 1833, W. Schimper 944 [Unio itineraria (1837)] ( G 00688924 !, image available at http://www.ville-ge.ch/musinfo/bd/cjb/chg/adetail.php?id=668392&base=img&lang=en); isotypes HBG 503188 , M 0241524 !).

= Achyranthes aspera var. simplex Millsp. , Publ. Field Columb. Mus., Bot. ser. 2: 36 (1900). Holotype: [ US Virgin Islands] St. Thomas , Charlotte Amalie, 17–18 January 1899, C. F. Millspaugh 484 (F – image!, isotype NY 658322 – image!).

= Achyranthes obovata Peter , Repert. Spec. Nov. Regni Veg. Beih. 40 (2, Anhang): 25 (1932) nom. illeg., non (M. Mart. & Gal.) Standl. (1915). Holotype: Deutsch-Ostafrika [ Tanzania, Tanga Region] West-Usambara, Mashewa, Gegend Tunya und Kwatangu , 400 m, 8–9 September 1915, A. Peter 13869 (B – image!).

Lectotype (designated by Townsend 1974).

[ Sri Lanka] Herb. Hermann 2: 69, no. 105 ( BM 000621744 !) .

Description.

(Fig. 11 ). Annual herb, 30–200 cm tall, stout, not rooting; young stem round, angled at the inflorescence; leaf petioles 10–30 mm, blades 15–110 × 20–80 mm, obovate or ovate, base truncate, pubescent throughout, tip shortly acuminate; inflorescence up to 70 cm long; bract 2.0– 2.5 mm long; bracteoles 2.5–3.5 mm long, green, not or slightly reflexed; perianth 4.0– 4.5 mm long, segments ± equal, one-veined with two indistinct lateral veins; stamens 5 with white or mauve filaments, anthers 0.4–0.6 mm long; pseudostaminodes 0.7–1.1 mm long, white; style with stigma 1.0– 1.1 mm long; fruit (without style) 1.8–2.2 mm long.

Taxonomic note.

Many authors ( Podlech 1966; Berhaut 1971; Townsend 1980 b; Ghazanfar 1992; Germishuizen and Meyer 2003; De Lange et al. 2004; Gibreel and Darbyshire 2015) indicated that A. aspera is a perennial herb occasionally flowering in the first year, but our field observations revealed that the species could be mistaken for a perennial based on its height and much branched habit in the moist regions (e. g., Zanzibar, Tanzania; Haryana, India: pers. obs. APS), but is a robust annual.

Nomenclatural notes.

The lectotype of Achyranthes aspera designated by Townsend (1974) and proposed for conservation by Jarvis (1992), although only represented by the upper part of a plant, clearly shows the characters typical of the taxon (obovate leaves, short bracteoles and flowers). Fawcett and Rendle (1914: 136) indicated that the type of A. aspera var. indica is kept at the Natural History Museum ( BM) and referred to Hermann’s Flora Zeylanica. This choice was formalised by Townsend (1985), who, therefore, made this varietal name a homotypic synonym of the type variety. Jarvis (2007) disagreed with Townsend (1985) and noted that Burman (1737) is the nomenclatural source of this Linneaen variety and should provide a type. Iamonico (2014) selected a lectotype of A. aspera var. indica in the herbarium S-LINN ( IDC 100.19) that is annonated by Linnaeus as “ β aspera ”. This sheet contains a fragment of the plant with three obovate leaf pairs and an inflorescence in early blooming stage. We have doubts whether this plant is the annual A. aspera , and we assume that the specimen in S-LINN rather belongs to A. porphyrostachya (although its leaf shape is not characteristic for the latter species). Despite these doubts, the protologue of A. aspera var. indica ( Linnaeus 1753) contains a separate diagnosis plus the indication that the variety occurs in “ India ” (“ Zeylona ” = Sri Lanka). This information links the Hermann’s specimen with the protologue and makes it part of the original material, thus eligible for lectotypification. For this reason, the type designation made by Townsend (1985) is formally correct and has priority over Iamonico’s choice; it stabilises the nomenclature of A. aspera as established by Townsend (1974, 1985) and universally accepted.

The protologue of A. obtusifolia ( Lamarck 1785) includes a number of cited illustrations which constitute its original material together with the specimens in the personal collection of Lamarck. A lectotype is therefore designated here.

Hassan et al. (2023) synonymized A. argentea var. obovata Moq. with A. sicula . Nevertheless, the holotype represents a branched specimen of A. aspera s. str. This lectotype is the only specimen used for and cited in the protologue ( Moquin-Tandon 1849), which is thus a holotype by definition; the lectotypification with the same specimen made by Hassan et al. (2023) was therefore superfluous.

The holotype of A. aspera var. simplex Millsp. is an unbranched specimen with a terminal inflorescence; its leaves are very typical of A. aspera .

Habitat.

Waste, mostly sunny places; frequent in the regions with humid climate (e. g., Unguja Island, Tanzania) at elevations of 0–1500 m a. s. l.

Distribution.

(Fig. 12 ; see also Appendix 1). Surprisingly, herbarium collections from the western part of Africa are scarce, indicating that it might be a scattered alien in the West Tropical Africa. The majority of collections are from the eastern tropical part of Africa and the islands in the western Indian Ocean, where it is usually considered as alien.

Africa: Benin, Cameroon, Chad, Comoros, DR Congo, Egypt (old record), Europa Island, Ethiopia, Ghana, Kenya, Liberia, Madagascar, Mauritius, Mayotte, Mozambique, Namibia, Réunion, Rwanda, São Tomé and Príncipe, Senegal, Seychelles, Somalia, South Africa, South Sudan, Tanzania, Uganda, Zimbabwe.

Arabian Peninsula: see Appendix 1.

General distribution.

The exact origin of the species is unknown, but it seems to be native in tropical South and South-West Asia. Because of the confusion of A. aspera s. str. with other species and varieties, we have detailed its distribution across the World based on the specimens seen in the herbaria visited and online collections.

Africa: see Appendix 1.

Asia: Bangladesh, Bhutan, Cambodia, tropical China including Hong Kong and Taiwan, India, Indonesia, Laos, Malaysia, Maldives, Myanmar, Nepal, Oman, Pakistan, Philippines, Saudi Arabia, Singapore, Sri Lanka, Thailand, UAE, Vietnam, Yemen (incl. Socotra).

Australasian Realm: tropical Australia, Papua New Guinea.

Melanesia: New Caledonia (probably other islands).

Polynesia: Pitcairn Island, Samoa. Also reported for many other islands of Polynesia ( Florence 2004).

America: Antigua and Barbuda, Bahamas, Barbados, Bolivia, British Virgin Islands, Brazil (tropical regions, e. g. States of Bahia, Espírito Santo, Minas Gerais, Pará), Colombia, Costa Rica, Cuba, Cayman Islands, Dominica, Dominican Rep., French Guiana, Grenada, Guadeloupe, Guatemala, Guyana, Haiti, Jamaica, Kingdom of the Netherlands ( Aruba, Bonaire, Curaçao, St. - Eustatius, St. - Martin), Martinique, Mexico, Montserrat (British Overseas Territory), Nicaragua, Panama, Puerto Rico, Salvador, St. Barthélemy (French Overseas Territory), St. Kitts and Nevis, St. Lucia, St. Vincent and the Grenadines, Suriname, Trinidad and Tobago, USA (Alabama, Florida, Louisiana, Texas, and Hawaii), US Virgin Islands.

It is common or frequent in disturbed places at lower altitudes in tropical America (e. g., Millspaugh 1900, as A. aspera obtusifolia ; Robertson 1981; Acevedo-Rodríguez and Strong 2012; pers. obs. of APS in Grenada in 2016).

Figures

Figure 11. Achyranthes aspera A an indoor cultivated plant in vegetative stage (grown from seeds from Unguja Island, Tanzania) B two bushy plants in fruiting stage (disturbed habitat on Unguja Island, Tanzania) C inflorescence of an indoor cultivated plant at fruiting D close-up view of a fruiting plant (disturbed habitat on Unguja Island, Tanzania). Photographer: A. Sukhorukov.

Figure 12. Distribution map of Achyranthes aspera.