Transfer of the Malagasy genera Humbertianthus and Macrostelia to Hibiscus (Malvaceae) with description of four new species
Hanes, Margaret M.
Schatz, George E.
Callmander, Martin W.
Candollea
2020
2020-10-29
75
2
193
202
7WM8F
M. Hanes & G.E. Schatz
M. Hanes & G. E. Schatz
2020
[801,1352,364,388]
Magnoliopsida
Malvaceae
Hibiscus
Plantae
Malvales
7
200
Tracheophyta
species
ankeranensis
sp. nov.
Holotypus: MADAGASCAR. Reg. Atsinanana [Prov. Toamasina]: Dist. Brickaville, Com. Maroseranana, Fkt. Ambodilendemy, Andrangato river, Ankerana, 18°26'52"S 48°46'28"E, 346 m, 13.III.2011, fl., Antilahimena7544( MO-2652132!; iso-: P[ P06774026]!, TAN).
Hibiscus ankeranensis M. Hanes & G.E. Schatzdiffers from H. calyculatus (Hochr.) M. Hanes, G.E. Schatz & Callm.by its epicalyces, 5 non-symmetrical, succulent in vivo lobes (vs. 4 small, reflexed lobes), calyx color, green (vs. red), and its nonreflexed petals. Treec. 6 mtall, 12 cmdbh; twigs moderately densely covered with light, golden, semi-erect, simple, fascicled and stellate trichomes. Leaves3.5– 9.8 × 1.9 –3.9 cm, elliptic to narrowly obovate, the base acute to obtuse, apex acuminate, the acumen to 1.2 cm, sometimes folded to one side, the tip rounded, glabrous and verruculose above, very sparsely covered with golden, stellate trichomes below, venation weakly brochidodromous with 7–10 secondary veins per side, with occasional intersecondary veins, midvein raised above and below, secondary veins slightly raised above and below, tertiary venation finely reticulate, slightly raised above and below; petiole 3–5 mm, 0.7–1 mmin diam., moderately densely covered with semi-appressed, curly light golden trichomes. Flowerssolitary, axillary, pendent; pedicels 7–15 mmlong, 0.2–0.7 mmin diam., densely covered with golden erect, simple and fasciculate trichomes; epicalyx with 5 free lobes, appearing somewhat succulent in vivo, the lobes 9 × 5 – 7 mm, ovate, the apex acute, sparsely covered with golden stellate trichomes on the outside, glabrous very sparsely covered with golden simple and stellate trichomes inside; calyx tubular with 4(–5?) lobes, fused for 5–7 mm, the lobes 2.5 × 2.5 mm, triangular, the apex triangular, moderately densely covered with golden stellate trichomes outside and inside; petals 5, 24 × 13 mm, obovate, the apex rounded to emarginate, red, sparsely covered with very light golden stellate trichomes outside, glabrous inside with evident venation; staminal column 20 mmlong, 0.8 mmin diam., pinkish red, glabrous with very scattered minute trichomes; stamens 30–40(–50), filaments 8–10 mm, red, anthers 0.8 × 0.4 mm; styles 5, 8 mm, red, moderately densely covered with white trichomes, stigma c. 0.7 mmin diam., urceolate. Fruitunknown.
Distribution and ecology. – Hibiscus ankeranensisis known only from a single collection near the Andrangato river at Ankerana in the eastern coast of Madagascarat c. 350 min elevation in lowland moist evergreen forests ( Fig. 2). Fig. 4. –Photographs of epicalyx and calyx of HibiscusL. A. Hibiscus analalavensisM. Hanes & G.E. Schatz; B. Hibiscus ankeranensisM. Hanes & G.E. Schatz; C. Hibiscus vohipahensisM. Hanes & G.E. Schatz. [ A: Ratovoson 2092; B: Antilahimena 7544; C: Razafitsalama 1409] [Photos: A:F. Ratovoson; B:P. Antilahimena; C:C. Birkinshaw]
Conservation status. – Hibiscus ankeranensisis known only from a single collection from the newly designated Corridor Ankeniheny-Zahamena protected area. We lack information on population size but lowland moist evergreen forests (below 800 m) are fragmented and heavily deforested in the region ( GAUTIER, 2018). Recent satellite imagery from Google earth [https://www.google.com/intl/en/earth] suggests that the collection site and the surrounding area is deforested or disturbed. Hibiscus ankeranensisis therefore assessed as “Critically Endangered” [CR B2ab(iii)] using IUCN Red List Categories and Criteria ( IUCN, 2012).
Notes. – Hibiscus ankeranensisis similar to H. calyculatusin corolla color but differs by its epicalyces with 5 lobes, 9 mmlong (vs. 4(–5) lobes, reflexed, 3–4 mmlong), calyx with 4(–5) teeth, green, succulent in vivo (vs. 5 teeth, red, inflated) and petals not reflexed (vs. reflexed).
3407889331
2011-03-13
P, P06774026, TAN
Antilahimena
Madagascar
346
-18.447777
Fkt. Ambodilendemy
21
48.774445
Dist. Brickaville, Com. Maroseranana
7
200
MO-2652132
1
Reg. Atsinanana [Prov. Toamasina
holotype