Macrostelia calyculata Hochr. in Notul. Syst. (Paris) 14: 232. 1952 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 7WM8H (Hochr.) M. Hanes, G. E. Schatz & Callm. M. Hanes, G. E. Schatz & Callm. 2020 Hochr. Magnoliopsida Malvaceae Hibiscus Plantae Malvales 1 194 Tracheophyta species calyculatus comb. nov.     Macrostelia calyculataHochr.in Notul. Syst. (Paris) 14: 232. 1952.   Vernacular name.– “Tsilaitra” ( Service Forestier 2046, 14420).  Distribution and ecology. – Hibiscus calyculatusgrows in medium elevation moist evergreen forests east of Fianarantsoa, in the massif of Andrambovato, in the Ampamaherana valley and near Kianjavato (D. Scherberich, pers. comm.) from 1155–1300 min elevation ( Fig. 2).  Conservation status. – Hibiscus calyculatusis known from 3 locations all encompassed in the Protected Area Network (Corridor Forestier Ambositra-Vondrozo and Ranofanana). Despite the very restricted Extent of Occurrence (EOO) of 12 km² and an Area of Occupancy (AOO) of 8 km², there appear to be no current threats to  H. calyculatus. Thus, the species is assigned a conservation status of “Least Concern” [LC] using the IUCN Red List Categories and Criteria ( IUCN, 2012), with the caution that this status is highly dependent on continued effective protection.   Fig. 1. –Photographs of flowers of  HibiscusL. A.  Hibiscus calyculatus(Hochr.) M. Hanes, G.E. Schatz & Callm.; B.  Hibiscus laurinusBaill.; C.  Hibiscus ambanitazensisM. Hanes & G.E. Schatz. [ B: Rasoandriana 89; C: J. Razanatsoa 644] [Photos: A:D. Scherberich; B:P. Antilahimena; C:B. Mashburn]  Notes. – Hibiscus calyculatusis distinguished from all other pendent  Hibiscuson Madagascarby its four small ( 3–4 mm), free, reflexed epicalyx bracts and a distinctive red, tubular calyx.  Additional specimens examined.–   MADAGASCAR. Reg. Vatovavy-Fitovinany[Prov. Fianarantsoa]: Massif d’Andrambovato, Tolongoina, Ikongo, 21°30'58"S 47°25'36"E,  1155 m,  28.V.1998, fl.,  Razafimandimbison335( G, MO, P, TAN, TEX);  Fort Carnot, Andrambovato Station Forestier, Parcelle A-16, [ 21°31'S 47°25'E],  28.VII.1954, fl.,  Service Forestier14420( P, TEF). 3407889326 1949-05-25 P, G, TEF Service Forestier Madagascar 1300 -21.316668 vallee Ampamaherana 1264 47.316666 vallee Ampamaherana 1 194 P00037125, G00014441 1 Reg. Haute Matsiatra [Prov. Fianarantsoa holotype 3407889319 1954-07-28 G, MO, P, TAN, TEX Razafimandimbison Madagascar Massif d'Andrambovato 1155 -21.516111 Ikongo 21 47.426666 Tolongoina 3 196 1 Reg. Vatovavy- Fitovinany [Prov. Fianarantsoa 3407889323 1954-07-28 P, TEF Service Forestier Madagascar Massif d'Andrambovato 1155 -21.516111 Andrambovato Station Forestier 21 47.426666 Fort Carnot 3 196 1 Reg.