Achyranthes abyssinica Nees

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 abyssinica Nees , Del. Sem. Hort. Vratisl. 1850: 3 (1851).

= Achyranthes aspera f. rubella Suess. , Bull. Jard. Bot. État Bruxelles 15: 56 (1938). Lectotype (designated here): DR Congo, [South Kivu Prov.,] Kizozi , 1935, Lejeune 190 ( BR 0000008819512 !, isolectotype BR 0000008819192 !).

= Achyranthes aspera [var. sicula] f. latifolia Suess., Mitt. Bot. Staatssamml. München 1: 70 (1951) . Holotype: Kenya, pr. Forest Station in silva montana, 2350 m, 5 January 1922, R. E. Fries & Th. C. E. Fries 781 ( K 000243724!, isotypes BR 0000008819922!, S 07-12310 – image!).

= Achyranthes argentea var. albissima Suess. , Mitt. Bot. Staatssamml. München 2: 70 (1955). Lectotype (designated here): Kenya, Northern Prov., Furroli [Mount], Mt. top: granite with Olea & Juniperus , 6600 ft, occasional, 20 September 1952, J. B. Gillett 13957 ( K 000243722!, isolectotype K 000243723!).

– Achyranthes sicula auct. div.

Neotype (designated here).

Ethiopia, [Tigray Region,] Scholoda [ Soloda Mt. near Adwa Town ], 12 November 1838, Schimper 1144 [Schimper, Iter Abyssinicum, ser. 2 (1842)] ( BM!, isoneotypes G 00688998 , BR 00000083356949 !, FI!, K 005771057 ! – central twig, LE!, M 0241524 !, WU!).

Description.

(Fig. 3 ). Annual, stout or rarely delicate herb up to 1.0 (1.5–2.0) m, not rooting at nodes, very rarely creeping at lower nodes; stem four-angled, sparsely pubescent, sometimes scrambling; lateral branches long and ± horizontally spreading; leaf petioles 10–25 mm long, blades 20–100 (120) × 10–40 (50) mm, broadly cuneate or truncate, ovate, entire, tip acuminate, bicolored: ± green, slightly to moderately pubescent above, whitish or grey below (sparsely pubescent and green when cultivated indoor); inflorescence 50–250 mm long, sometimes pendulous; bract ~ 2.0 mm long; bracteoles 2.5–3.0 mm long, reflexed; perianth (3.5) 4.0–4.5 (5.0) mm long, green or purplish inside; pseudostaminodes 0.6–1.0 mm long, short, white or pink, fimbriate or not; stamens 5, with pink filaments, anthers 0.4–0.7 mm long, pink or magenta; style (1.3) 1.8–2.5 (3.0) mm long, pink; fruit (without style) (1.3) 1.8–2.5 (3.0) mm long.

Taxonomic notes.

Morphologically, A. abyssinica is similar to A. sicula but differs from the latter by a slightly longer perianth and style, although a few specimens from tropical Africa have the same style length as in A. sicula . Although these two species are very similar in morphology, as also shown in our identification key, they take different positions in the molecular phylogeny (unpublished). Both species have clearly different and non-overlapping distributions, with A. abyssinica growing in mountainous areas of East and Central Africa and South Arabia, whereas A. sicula is a subtropical species found in areas with a Mediterranean climate.

Nomenclatural notes.

Unfortunately, the whereabouts of the type specimens of Achyranthes abyssinica in the Nees herbarium are mostly unknown because this collection had been split into numerous parts, which were sold to institutions or private individuals ( Stafleu and Cowan 1981). The contents of these parts are not always certain; besides, the collection was heavily affected by extensive losses in German herbaria during the Second World War. Our request to Bonn, where these type specimens were possibly kept, was unsuccessful because that Herbarium was completely destroyed during the war (Thomas Joßberger, pers. comm.). There are also no authentic specimens in STR (Gisele Haan-Archipoff, pers. comm.) and LE (Sukhorukov, pers. obs.), where large parts of Nees collections are housed.

In the absence of any original material, we designate Schimper’s collection from Ethiopia, which was prepared in numerous duplicates and commercially distributed to many Herbaria under the name A. argentea , as the neotype of A. abyssinica .

The label of the isolectotype of A. aspera f. rubella Suess. gives no exact location information, but both specimens belong to a single gathering (Lejeune 190). No other specimens of the original material are known, and the type choice is therefore rather formal.

Suessenguth in Suessenguth and Merxmüller (1951) cited the type of A. aspera f. latifolia Suess. as kept at Kew. The duplicates in BR and S are, therefore, isotypes.

Achyranthes argentea var. albissima Suess. comprises mountainous plants with small white leaves. Suessenguth in Suessenguth and Merxmüller (1951) designated two specimens of a single gathering at Kew as “ typus ”. These specimens are syntypes; a lectotype is designated here to restrict the typification to a single specimen.

Habitat.

Open or slightly shady grassy slopes, bushy vegetation, calcareous outcrops, sometimes as a weed, at elevations of 1000–3500 m a. s. l. in arid or seasonally moist areas.

Distribution.

(Fig. 4 ; see also Appendix 1). Africa: Angola, Burundi, Cameroon, DR Congo, Eritrea, Ethiopia, Guinea, Kenya, Madagascar, Malawi, Nigeria, Rwanda, Somalia, South Sudan, Sudan, Tanzania, Uganda.

Arabian Peninsula: Oman, Saudi Arabia, Yemen.

General distribution.

The species is only known from tropical Africa and Arabia.

Figures

Figure 3. Achyranthes abyssinica A an indoor cultivated plant in vegetative stage (grown from seeds from Arusha Region, Tanzania) B flowering twig in bushy vegetation in Meru area, Arusha Region, Tanzania. Photographer: A. Sukhorukov.

Figure 4. Distribution map of Achyranthes abyssinica.