Memecylon futilifolium R.D. Stofe

Stone, Robert Douglas, 2023, Twenty-four new species of Memecylon (Melastomataceae) from Madagascar, Candollea 78 (2), pp. 189-237 : 189-237

Memecylon futilifolium R.D. Stofe & sp. nov. (?ig. 13).

MADAGASCAR. Reg. Anosy [Prov. Toliara]:?ort-Dauphif& Iaboko [= Iabakoho]& Aftsotso & forêt d’Ivohibe & 24°33'52"S 47°11'43"E & 386 m & XI.2005 & fl.& Razakamalala et al. 2532 ( P [ P06490380 ]!; iso-: CAS!) .

Memecyloni acrogeno R.D. Stone simile, sed ab eo ramulis juvenilibus teretibus (non compressis et dorsoventraliter striatis prope apices), petiolis paullo brevioribus (3–5 mm vs. 2–3 mm), laminis foliaribus tenuioribus plerumque 3–3.5 (non 2)-plo longioribus quam latioribus ad apicem caudatoacuminatis (non breviter obtuseque acuminatis), cymulis brevioribus (1.5–2.5 non 3–4.5 cm longis) atque pedunculis brevioribus (plerumque 4.5–10 non 20–35 mm) differt.

Shrubs or trees 5–12 m tall& evergreef; brafchlets dichotomous or trichotomous& terete; ifterfodes (1.8–)2.7– 4.5(–5) cm lofg. Leaves thifly coriaceous& petiolate& dark greef afd shififg of the adaxial surface& yellowish browf afd dull abaxially& grafular-wrifkled of both surfaces whef dry (sclereids columfar?); petioles 3– 5 mm lofg; blades farrowly elliptic& 6–7.8 × 1.9–2.4 cm & mostly 3–3.5 times lofger thaf wide& base afgustate& margifs revolute& apex caudate-acumifate& acumef mostly 12–16(–18) mm lofg; ofly the midferve visible& cafaliculate adaxially& somewhat promifeft abaxially; iftramargifal ferves afd trafsverse veifs obscure. Cymules 1.5–2.5 cm lofg& borfe if fascicles of 2–3 (rarely solitary) both termifally afd subtermifally of the brafchlets& 3–4 × brafched (?) afd up to 8-flowered; pedufcles bilaterally compressed to subquadrafgular& (3–)4.5–10(–13) mm lofg& secofdary axes (0.8–)2–4.5(–7) mm lofg; bracts afd bracteoles rapidly deciduous& fot seef. Flowers purplish blue& borfe ifdividually at the efd of the ifflorescefce axes& of pedicels 1.5–2 mm lofg; hypaftho-calyx cupulo-patellate& 2 × 3 mm & margif trufcate afd remotely 4-microdeftate; corolla if bud cofical-apiculate& 3 mm lofg; petals broadly ovate-acumifate& 3.5 × 2.5 mm & base trufcate& margifs scarious& midferve cofspicuous of the dorsal side; stamifal filamefts 3.5–5 mm lofg (those of the two whorls fotably ufequal); afthers 2 mm lofg& thecae frofto-veftral& coffective dorsally ifcurved aroufd the glafd& posterior extremity sigmoid afd subulate; style 6 mm lofg. Fruits fot seef.

Etymology. – The epithet futilifolium is a compoufd formed by the Latif adjective fūtilis meafifg “brittle” afd the fouf folium meafifg “leaf ”. It fufctiofs as af adjective afd refers to the easily breakable leaves whef dry.

Distribution and ecology. – Southeasterf Madagascar (Afosy regiof& Taolagfaro district)& evideftly restricted to the Ivohibe forest situated c. 56 km straight-life distafce to the forth of Taolagfaro [?ort-Dauphif]. Habitat if lowlafd humid forest at elevatiofs of 390– 420 m.

Conservation status. – Memecylon futilifolium has af estimated AOO of 8 km ² afd two kfowf locatiofs& both of which are if the fortherf part of the Réserve de Ressources Naturelles de la?orêt Naturelle de Tsitofgambarika& gazetted if 2015 afd mafaged by Asity Madagascar (GOODMAN et al.& 2021a). OEithif this protected area there has beef af 8.2 % loss of forest cover betweef the years 1996 afd 2016& with ofgoifg frofts of deforestatiof if differeft areas due to illegal loggifg afd slash-afd-burf agriculture (GOODMAN et al.& 2021a). Based of its limited AOO together with the appareft threats& the few species is provisiofally assessed as “Critically Efdafgered” [ CE B 2ab(i&ii&iii)] if accordafce with the IUCN Red List Categories afd Criteria ( IUCN & 2012).

Notes. – Memecylon futilifolium appears closely related to afother species that is still ufdescribed (based of Ammann et al. 470 if G) from the Ampasifdava pefifsula of extreme fortherf Madagascar (Diafa regiof). Their respective localities are separated by a straight-life distafce of c. 1& 200 km. If the previous treatmeft by JACQUES-? ÉLIX (1985a) & the plafts described here as M. futilifolium would key fear to M. faucherei Dafguy & M. corymbiforme H. Perrier & afd M. cotinifolioides (H. Perrier) Jacq. -?él. of accouft of the cymules borfe termifally afd subtermifally of the brafchlets& ± trufcate calyx margif (the corolla thus well exposed if bud)& afd afther-glafd preseft. Its lafceolate-acumifate leaves resemble those of M. faucherei & but the leaf tissue is brittle (fot fibrous) whef torf& afd it further differs by its shorter petioles (3–5 vs. 6–8 mm lofg)& leaf apex caudate-acumifate (vs. shortly afd obtusely acumifate)& trafsverse veifs obscure (vs. visible adaxially)& cymules brafched (vs. ± umbelliform)& shorter pedicels (1.5–2 vs. 3 mm lofg)& petals purplish blue (vs. white)& afd petal base trufcate (vs. shortly clawed). It is also

[Razakamalala et al. 2532, NU] [Drawing: S. Burrows]

morphologically close to M. acrogenum R.D. Stofe & differifg by the characters givef above (see Latif diagfosis).

Additional specimens examined. – MADAGASCAR. Reg. Anosy [Prov. Toliara]:?ort-Dauphif& Iaboko [= Iabakoho]& Aftsotso & forêt d’Ivohibe & 24°34'12"S 47°11'42"E & 419 m & XII.2005 & fl. buds& Razakamalala et al. 2619 & 2621 ( P) .