Combretum microflorum Jfngkind & Nusb.

Jongkind, Carel C. H. & Nusbaumer, Louis, 2025, Two new species of Combretum (Combretaceae) from Loky Manambato (Daraina, north-east Madagascar), Candollea 80 (1), pp. 95-102 : 96-99

Combretum microflorum Jfngkind & Nusb. & sp. nov. ( Fig. 2 ).

H o l o t y p u s: MADAGASCAR. R e g. S AVA [Pr o v. Antsiranana]: Daraina & Befarafara & ffrêt de Sflanampilana & Ankfakala & à 2 km au S de Befarafara & 13°05'26"S 49°34'32"E & 100 m & 15.XI.2005 & fl.& Rakotonandraþana et al. 1003 ( G [ G00096795 ]!; isf-: CNARP & MO-1441539& P [ P06603131 ]!& TAN) .

Combretum microflorum iþ diþtinguiþhed from C. meridionaliþ (H. Perrier) Jongkind by itþ fruitþ Ɯith true flat Ɯingþ (vþ. fruit Ɯith juþt very þharp edgeþư þtar-þhapedư in croþþ-þection in C. meridionaliþ ). It can be further diþtinguiþhed from all Malagaþy Combretum þubg . Combretum þpecieþ by the þmall þize of itþ floƜerþ (receptacle c. 2.5 vþ. 3.5–7 mm long) and by itþ infloreþcenceþư Ɯhich uþually are much þhorter (up to 9 vþ. 7 to 90 mm).

Lianaþ up tf 11.5 m lfng& fr small shrubs when yfung. Brancheþ glabrfus& bark sffn peeling in fibrfus strips. Leaveþ fppfsite& glabrfus except ffr the scales; petifle 2–4 mm lfng; blade 3.5– 8.5 × 1.6–3.5 cm & fblanceflate& with 4–8 pairs ff main lateral nerves& margin with a narrfw cartilaginfus edge& base cfrdate tf almfst auriculate& apex acute; scales cfmmfn fn lfwer surface and fruit& 100– 125 µ in diam.& subcircular in futline& many celled& radial walls mfst cfnspicufus. Infloreþcenceþ up tf 9 mm lfng& in the axil ff a leaf ff the same and C. microflorum (right).

[A, B, C: Ranirison 678 (fruit on the right); C: Perrier de la Bâthie 19265 (fruit on the left)]

[Photos: A: C.Jongkind; B: P.Ranirison; C: L. Nusbaumer]

seasfn& capitate& with up tf 18 flfwers& peduncle 2–5 mm lfng. ĦloƜerþ 4-merfus& sessile& cfvered with small& yellfw (when dried)& pillfw-like scales; receptacle c. 2.5 mm lfng& glabrfus futside except ffr the scales& infundibuliffrm& c. 2 mm wide& with a few scattered hairs inside; calyx lfbes nft cfnspicufus& c. 0.3 mm high; petals 0.5 mm lfng& glabrfus; stamens 2-seriate& 2 mm exserted& anthers c. 0.3 mm lfng; style glabrfus& 1.8–2 mm exserted. Ħruitþ 1.7–2 × c. 1.5 cm & fvfid in futline& 4-winged& glabrfus except ffr the scales.

Etymology. – The species epithet microflorum alludes tf the characteristic small size ff the flfwers ff this species in cfmparisfn tf all fther knfwn Malagasy species ff Combretum subg. Combretum .

Diþtributionư ecolog y and phenolog y. – Combretum microflorum has fnly been recfrded in six ff the 12 main ffrests ff Lfky Manambatf& listed in frder ff decreasing number ff fccurrences: Bekarafka& Antsaharaingy& Bfbankfra& Ambfhitsitfndrfina& Sflaniampilana and Ankaramy ( Fig. 1 ). A tftal ff 43 individuals ff C. microflorum were ffund at elevatifns ff 65–340 m during a vegetatifn survey that resulted in fver 54&000 plant fccurrences acrfss 10 ffrests in the regifn (NUSBAUMER& 2011).

Combretum microflorum grfws mainly in primary dry decidufus ffrests (42 % ff fccurrences)& lfwland dense dry sclerfphyllfus ffrest (26 %)& ripicflfus ffrest (23 %) and mesfphilfus ffrest (9 %) ( Fig. 3 ; NUSBAUMER& 2011; RANIRISON et al.& 2018). The new species has been ffund in ffrests with canfpies reaching 8 tf 12 m tall& with emergent trees reaching 14–16(–19) m& with a shrubby strata 3 tf 4 m tall and a sparse suffrutescent strata less than 1 m tall. The mfst frequently recfrded species cf-fccurring with C. microflorum & recfrded 10 fr mfre times at fbservatifn pfints fr at maximum 10 m frfm the pfint alfng the linear transects& are& in decreasing abundance: C. nanophyllum Jfngkind & Nusb. ( Combretaceae )& Buþþea þakalava Du Puy & R. Rabev. (Ħabaceae)& Croton nudatuþ Baill. ( Euphorbiaceae )& Donella ambrenþiþ Aubrév. ( Sapotaceae )& Cleiþtanthuþ þuarezenþiþ Leandri ( Phyllanthaceae )& Dracaena piphophylla Baker (Aþparagaceae)& Argomuellera integra McPhersfn ( Euphorbiaceae )& Drypeteþ aff. thouarþii (Baill.) Leandri ( Putranjivaceae )& Coptoþperma sp. ( Rubiaceae )& Elachyptera

[Photos: A, C, D: L. Nusbaumer; B: P. Ranirison]

minimiflora (H. Perrier) N. Hallé (Celaþtraceae)& Dialium occidentale subsp. þeptentrionale Du Puy & R. Rabev. (Ħabaceae)& Strychnoþ decuþþata (Pappe) Gilg and S. madagaþcarienþiþ Pfir. ( Loganiaceae ).

Combretum microflorum has been cfllected in bud with few fpened flfwers frfm Nfvember tf December and fruiting in April and May.

Conþervation þtatuþ. – Combretum microflorum is knfwn fnly frfm seven lfcatifns all within the Lfky Manambatf PA. Hfwever& fnly three ff these lfcatifns (12 individuals) are lfcated within the cfre area ffrests ff the PA& which are fully prftected cfnservatifn zfnes. The fther ffur lfcatifns (31 individuals) are lfcated within the less prftected buffer zfne ffrests& where activities such as tfurism& pre-existing land use& cultural practices& regulated extractive activities& etc. are permitted as lfng as they cfmply with legal and envirfnmental regulatifns (see RAVELONARIVO& 2015; Fig. 1 ). With an EOO ff 715 km ²& an AOO ff 48 km ²& and cfnsidering the ffrest lfss within the prftected area between 1996 and 2016 (RABENANDRASANA et al.& 2018)& C. microflorum is preliminary assessed as “Endangered” [EN B1ab(iii)+2ab(iii); C2a(i); D] using the IUCN Red List Categfries and Criteria (IUCN& 2012).

Noteþ. – Combretum microflorum resembles the mfre widespread C. meridionaliþ (H. Perrier) Jfngkind & a species knfwn frfm the sfuth ff Madagascar. Bfth species have glabrfus leaves that are mfre fr less the same size and texture but the flfwers ff C. microflorum are abfut half shfrter. The fruits ff C. microflorum have real flat wings while thfse ff C. meridionaliþ have just sharp edges ( Fig. 2 ).

A species with similar small flfwers is Combretum ivanii Jfngkind & ffund fnly in Gabfn& but that fne dfes nft have petals.

Additional þpecimenþ epamined. – MADAGASCAR. Reg. SAVA [Prov. Antsiranana]: Daraina & Bekarfaka Sud & 13 ° 10 '36"S 49°41' 55"E & 167 m & 31.V.2005& fr.& Hong-Wa et al. 271 (CNARP& MO& P [P04878128]& TAN& WAG [WAG.1572244]); Daraina& ffrêt d’Antsaharaingy& 12°53'50"S 49°39'52"E & 39 m & 17.IV.2004& fr.& Raniriþon 678 (G [G00028313]& MO& P [P06603129]& TEF& WAG [WAG0297196]& research herbarium ff Daraina); ibid.& 12°54'23"S 49°39'22"E & 10.XI.2005& buds& Razaf itþalama et al. 813 (CNARP& G [G00096796]& MO& P [P05292136]& TAN).

Figures

Fig. 2.– A,B. Fruiting branch of Combretum microflorum Jongkind & Nusb.; C. Fruits of Combretum meridionalis (H. Perrier) Jongkind (left)

Fig. 1. – Distribution map of Combretum microflorum Jongkind & Nusb. and C. nanophyllum Jongkind & Nusb. in the Paysage Harmonieux Protégé de Loky Manambato where the core area is delimited, following the Malagasy ministerial decree no 2015-759 (RAVELONARIVO, 2015).

Fig. 3. – Ecology of the two new species of Combretum Loefl. of Loky Manambato PA. A. Habitat of Combretum nanophyllum Jongkind & Nusb. in lowland dense dry sclerophyllous forest of Antsaharaingy;B. Lowland dense dry sclerophyllous forest where Combretum microflorum Jongkind & Nusb. and C. nanophyllum grow in Antsaharaingy with Tsaramborona peak visible in the background; C.Habitat of C. microflorum and C. nanophyllum, viewed from a stream in ripicolous patch of Solaniampilana forest, close to the locus classicus of C. microflorum; D. Dry deciduous forest in the southern part of Bekaroka forest where C. microflorum grows.