Clerodendrum thouarsii Phillipson & Callm., 2016

Phillipson, Peter B. & Callmander, Martin W., 2016, Two varieties of Clerodendrum L. (Lamiaceae) from Madagascar raised to specific rank, Candollea 71 (2), pp. 373-377 : 376-377

Clerodendrum thouarsii Phillipson & Callm. , nom. nov.

÷ Clerodendrum aucubifolium var. longiflorum Moldenke in Bull. Torrey Bot. Club 77: 393. 1950 [non C. longiflorum Decne. ].

Typus: MADAGASCAR. Prov. Toamasina: sine loc., s.d., du Petit Thouars s.n. (holo-: P [ P00440399 ]!).

Etymology. – Clerodendrum thouarsii is named in honour of Louis Marie Aubert du Petit Thouars (1758-1831), who spent six months in Madagascar between July 1795 and January 1796 (Allorge & Ikor, 2012). He collected mainly along the east coast around Toamasina where he probably collected the type specimen of this species and annoted on his collection the name: “Volkameria longiflora P.”, but this name has never been validely published. Du Petit-Thouars (1806) described many genera in Madagascar, and also several species, notably orchids ( du Petit-Thouars, 1822).

Vernacular names. – “Antambe” (Service Forestier 8603); “Ramidongana” (Service Forestier 26260); “Ravinatamba” (Réserves Naturelles 6661); “Antafana” (Réserves Naturelles 12125).

Distribution, ecology and conservation status. – Clerodendrum thouarsii is known from humid forest from eight localities, on the eastern escarpment of Madagascar in a restricted area between Betampona and Fenoarivo near the east coast, and inland towards Lac Alaotra. Four of the collection localities fall within the protected area network (Betampona and Zahamena), but others lie outside. Therefore, with an extent of occurrence (EOO) of <20,000 km 2 and a projected continuing decline of lowland evergreen primary forest outside the protected area network, C. thouarsii can be assigned a preliminary risk of extinction of “Vulnerable” [VU B1ab(i,iii,iv,v)] following IUCN Red List Categories and Criteria ( IUCN, 2012).

Observations. – Moldenke (1950) did not provide a direct comparison between this plant and his var. giganteum , distinguishing it from typical C. aucubifolium by its larger coriaceous leaves borne on very stout petioles, by its long broad calyx and by long slender corolla tube and large corolla. Further differences between the three species are discussed in detail above, and summarized in Table 1. A new combination at species level based the varietal name “ longiflorum ” cannot be established since the name C. longiflorum Decne. already exists as a valid name for a species occuring in South-East Asia and Australia.

Other specimens examined. – MADAGASCAR. Prov.Toamasina: Vavatenina, Sahatavy, Sahalangina , 17°27’04”S 48°57’17”E, 450 m, 24.X.2000, Andrianjafy & Andriamiarisoa 114 ( MO, P, TAN, TEF); Betampona NP , 17°55’S 49°13’E, 300-400 m, 5.X.1994, Andrianarisata et al. 213 ( MO, P, TAN); Ambalahady, Vavatenina , [17°28’36”S 49°11’25”E], 100 m, 4.X.1940, Cours 1540 ( P); Betampona NP , 250 m, 17°55’S 49°13’E, 3.X.2000, Iambana & Fidel 291 ( P); env. de Fénérive . [17°22’S 49°21’E], c. 100 m, Perrier de la Bâthie 10197 ( P [2 sheets]); Vavatenina, Ambodimangavalo, Manakambahiny I , près du PN de Zahamena , 17°34’S 48°57’E, 18.X.2000, Ratovoson 291 ( CNARP, MO, P, TEF); Betampona NP , [17°55’S 49°13’E], [300-550 m], 4.XI.1953, Service Forestier 8603 ( P [2 sheets]); Vavatenina, Antananolobe , [17°27’S 49°00’E], 13.X.1966, Service Forestier 26260 ( P, TEF); Betampona NP , 4.X.1954, Réserves Naturelles 6661 ( P); ibid. loc., 12.VII.1958, Réserves Naturelles 9734 ( P); Zahamena AP , 28.VI.1962, Réserves Naturelles 12125 ( P). SINE LOC.: s.d., Lastelle s.n. ( P).