Achyranthes seychellensis Sukhor., 2024

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 seychellensis Sukhor. sp. nov.

Holotype.

Seychelles, Farquhar Atoll , coconut plantation, 18 August 1984, G. Ogureeva 608 ( MW 0586306 !, isotype LE 00019370 !).

Description.

(Fig. 16 ). Annual herb up to 1.5 m tall; stem stout, basally ± roundish, four-angled in the inflorescence; leaf petioles 10–25 mm long, blades 80–120 × 30–60 mm, cuneate, tip shortly acuminate, green above and pale green below, slightly pubescent on veins; inflorescence up to 25 cm long with hirsute axis; bract 3.5–4.0 mm long; bracteoles 3.2–4.0 mm long; perianth 4.5–5.5 mm long, ± equal, deep rose or purple inside; stamens 5, anthers 0.75–1.0 mm long; pseudostaminodes 1.25–2.0 mm long, brownish or white when dry, fimbriate; style with stigma 2.2–2.7 mm long; fruit (without style) ± 2.0 mm long.

Habitat.

Calcareous and rocky areas at elevations of 0–200 m a. s. l. It can be a common weed in coconut plantations.

Flowering at fruiting.

Around the year.

Additional specimens seen.

Seychelles: Sèche Island , 23 Jan 1938, Ves 6149 ( K) ; St. Pierre Island , Oct 1960, C. J. Pigeott s. n. ( K) ; Aride Island , Feb 1983, F. Friedmann 4469 ( P 00804851 ) & Apr 1987, F. Friedmann 5455 ( P 00804847 ) ; Bird Island , 28 Sep 1952, E. S. Brown s. n. ( BM) ; Cousin Island , 25 Jan 1970, F. R. Fosberg 52173 ( K) ; Fouquet Island , 5 Apr 1976, D. R. Stoddart 7148 ( K) ; Farquhar Atoll (South), 2 Oct 1967, Gwynne & Wood 1189 ( K) ; Farquhar Atoll (North), 19 Sep 1968, D. R. Stoddart 1376 ( K) ; Aride Island , Jul 1975, Warman 23 ( K) ; Rémire [Eagle] Island , 25 Oct 1976, S. A. Robertson 2319 ( K) ; Bird Island , Mar 1976, D. R. Stoddart 7079 ( K) ; Denis Island , 10 Dec 1977, D. R. Stoddart 8086 ( K) ; Platte Island , 26 Feb 1980, S. A. Robertson 3021 ( K) ; Poivre Island , 6 Aug 1984, L. Averyanov & al. s. n. ( LE, MHA) ; Farquhar Atoll , 16 Aug 1984, L. Averyanov & al. 580 ( LE) .

Mauritius: Chagos Archipelago, Diego Garcia Atoll, East Island , 26 Jul 1967, D. R. Stoddart 875 ( K) ; Diego Garcia , near north coast, 30 Mar 1971, A. M. Hutson 15 ( BM) ; Sea Cow Island , 21 Feb 1975, M. J. D. Hirons 50 ( K) .

Relationship.

Friedmann (1994) reported three varieties of A. aspera : var. aspera, var. velutina , and var. fruticosa from the Seychelles. The specimens seen were identified as var. aspera or var. velutina . From A. aspera , the new species differs by longer leaf blades (80–120 × 30–60 mm vs. 15–110 × 20–80 mm), and longer anthers (0.75–1.0 mm vs. 0.4–0.6 mm) and styles (2.2–2.7 mm vs. 1.0– 1.1 mm). The true A. velutina Hook. & Arn. from the Pacific ( Samoa, Tahiti, Tuamotu etc.) is a hirsute shrub with longer (ca. 7 mm long) perianths, but some other characters, i. e. length of anthers and styles are similar. Several specimens from the Aldabra Islands identified as ‘ var. fruticosa ’ represent plant fragments with a woody base and need further evalution.

General distribution.

Endemic to the Seychelles and Chagos Archipelago.

Figures

Figure 16. Holotype of Achyranthes seychellensis Sukhor., sp. nov. (Seychelles, Farquhar Atoll, coconut plantation, 18 Aug 1984, G. Ogureeva 608, MW 0586306).