Homalium maringitra H. Perrier

Wendy L. Applequist, 2016, Revision of the Malagasy species of Homalium sect. Eumyriantheia Warb. (Salicaceae), Candollea 71 (1), pp. 33-60 : 46-47

7. Homalium maringitra H. Perrier in Mém. Mus. Natl. Hist. Nat. 13: 298. 1940.

Lectotypus (first step, designated by Sleumer, 1973: 319): Madagascar. Prov. Toamasina: Analamazaotra, 800 m, I.19 ??, fl., Perrier de la Bâthie 6725 ( P; isolecto-: BM, K).

Lectotypus (second step, designated here): Madagascar. Prov. Toamasina: Analamazaotra , 800 m, I.19 ??, fl., Perrier de la Bâthie 6725 ( P [ P00624063 ]! ; isolecto-: P [P00624062]!, BM, K [K000231475] image seen, PRE [ PRE0297346 -0] image seen, S [ S-G-3252 ] image seen, TAN [ TAN000244 ] image seen, US [ US00114727 ] image seen) . Syntypus: Madagascar. Prov. Toamasina: forêts montagneuses de l’Est, s.d., fl., Louvel 250 ( P [ P00624061 ]!).

Tree to 25 m tall, 28 cm dbh; large twigs grayish (to brown); young twigs dark brown, glabrous; stipules deltoid to lanceolate, 0.6-1.5 mm, glabrous to minutely pubescent. Leaves alternate; petiole (2-)3-5.5(-8) mm, glabrous; blade elliptical (narrowly elliptical to oblong-elliptical, obovate), (2-)3.6-5.3(-7.5) × (1.4-)1.8-3.3(-3.7) cm; base rounded to convex (cuneate, basally attenuate); apex round, occasionally emarginate (acute to obtuse with rounded tip); margins bearing several small teeth per side (or shallowly wavy) with small glands; abaxial surface glabrous, drying olive to medium brown; adaxial surface glabrous, drying usually paler, grayish or gray-green to tan (dark brown). Inflorescences racemes or narrow racemiform panicles with short 2-flowered branches, lateral, (3.2-)4.3-7.8(-12) cm, minutely pubescent (to glabrous proximally); peduncle (0.6-)1.4-4(8.5) cm, slender and somewhat flat; pedicel (0.5-)1.5-5(-6) mm, short-pubescent; bracts ovate to broadly deltoid, 0.6-1(-1.5) mm, glabrous to short-pubescent; bracteoles ovate to broadly deltoid, 0.3- 0.6(-1) mm, glabrous to short-pubescent. Flowers: sepals green to pinkish or yellowish green, 4-5, ovate to oblongovate (somewhat elliptical to narrowly elliptical, narrowly oblong) with rounded (acute) apex, 2-3.5 mm, abaxial surface sparsely short-pubescent to glabrous; calyx cup funnelform, sparsely short-pubesecent to glabrate; sepal glands orange or yellow, semicircular to irregularly rectangular, (0.6-)0.8- 1.4 × (0.4-) 0.5-0.7 mm, short-pubescent above and sometimes beneath; petals white to greenish, yellowish green, white with pink spots, or yellowish pink, elliptical to obovate or narrowly obovate with a short narrow base, rounded (acute) apex, 3.6-6 × 1.5-2.8 mm, often almost twice as long as sepals, abaxial surface short appressed-pubescent (to glabrous at margins), adaxial surface glabrous (rarely sparsely pubescent towards base); filaments 1.5-2.5 mm, glabrous; anthers yellow, 0.4- 0.5 mm; ovary nearly flat, appressed-pubescent; styles 4, 0.7-2.5 mm, basally appressed-pubescent. Seeds not seen.

Vernacular names. – “Ampitsikahitra” (Louvel 250); “Hazomalany” (Antilahimena & Razafindasy 3500); “ Maringitra ” (Perrier de la Bâthie 6725).

Distribution, ecology and conservation status. – Homalium maringitra is found in mid-elevation humid forests; it is reported to occur on laterite. The species is only known from two small, well-separated regions, with less than five clearly distinct locations. Most collections have been made from the eastern site of Ambatovy near a mining project, extending to the nearby southern end of the Mantadia national park; two others have come from the much more northerly reserve of Anjanaharibe-Sud. The first-mentioned location is obviously threatened by human activity, and the species’ area of occupancy is, as a consequence of the number of collections, less than 500 km 2. Hence, a preliminary assessment of conservation status as “Endangered” [EN B2ab(iii)] would be appropriate.

Notes. – Sleumer (1973) designated Perrier de la Bâthie 6725 as lectotype and marked both sheets held at P as “Syn & Lectotype ” with no indication of preference between them. Art. 9.17 of the ICN ( McNeill et al., 2012) recommends that a second-stage lectotypification be published; the sheet with better inflorescences is herein selected.

Homalium maringitra is notable for its small elliptical leaves and small flowers with short, sparsely pubescent to glabrous sepals yet densely pubescent sepal glands. It is believed to form a natural group with the newly described rare species H. dorrii and H. ranomafanicum . The former has often narrowly obovate leaves and longer sepals, both absolutely and relative to the petals, and is found in low-elevation forest on laterite, while the latter has often broadly obovate leaves, with revolute to subentire margins and few glands, and long paniculate inflorescences and is found in southeastern mid-elevation forest.

Additional material examined. –. Prov. Mahajanga: Anjanaharibe-Sud, Anjiamazava , suivant la route Nationale d’Andapa-Bealanana, piste vers le N approchant le sommet de Bevitsika , 14°42’S 49°27’E, 1100 m, 14.XII.1994, fl., Ravelonarivo & Rabesonina 560 ( G, MO, P) ; Manandriana , versant W d’Anjanaharibe-Sud RS, forêt d’Anjiamazava , 14°48’S 49°27’E, 961 m, 3-7.II.1997, fl., Ravelonarivo et al. 1064 ( G, K, MO). Prov. Toamasina: Fkt. Menalamba, Ambatovy , forêt d’Analamay, 18°49’27”S 48°20’13”E, s.d., fl., Andriatsiferana 2549 ( MO) ; Fkt. Menalamba, Ambatovy forest up to Berano village, 18°50’13”S 48°19’19”E, 1130 m, 17.I.2005, fl., Antilahimena et al. 3202 ( MO, P) ; Fkt. Berano, Ambatovy forest, 18°49’14”S 48°20’07”E, 1120 m, 3.II.2005, buds, Antilahimena et al. 3278 ( P) ; ibid. loc., 18°49’19”S 48°20’08”E, 1094 m, same date, fl., Antilahimena et al. 3297 ( MO, P) ; ibid. loc., 18°48’33”S 48°19’22”E, 1074 m, 17.II.2005, fl., Antilahimena et al. 3420 ( MO, P) ; ibid. loc., Analamay, 18°51’36”S 48°18’03”E, 1134 m, 1.III.2005, post-fl., Antilahimena & Razafindasy 3500 ( MO, P) ; ibid. loc., Ampangadiantrandraka forest, 18°51’45”S 48°17’44”E, 1035 m, 4.III.2005, fl., Antilahimena & Félix 3579 ( P) ; Fkt. Menalamba, Ambatovy forest, 18°50’22”S 48°18’47”E, 1142 m, 24.I.2007, fl., Antilahimena et al. 5205 ( P) ; Fkt. Falierana, Mantadia , S boundary of Mantady forest, 18°53’22”S 48°26’53”E, 997 m, 14.XII.2013, fl., Antilahimena et al. 8792 ( P) ; Andasibe, forêt de Maromizaha , 18°57’56”S 48°27’34”E, 1020 m, 1.IV.1999, fl., Labat et al. 3069 ( MO, P) ; Ambatovy, nickel-mining exploration site, plot 18 of Golder map, 18°51’12”S 48°18’48”E, 1100 m, 26.II.1998, fl., McPherson 17471 ( MO) ; Phelps Dodge project site, Ambatovy , SE valley, contour line PDM-Pit-8, 18°51’24”S 48°17’41”E, 1000 m, 6.III.1997, fl., Rakotomalaza et al. 1242 ( MO, P) ; Ambatovy , 18°51’33”S 48°17’40”E, 990 m, 25.III.1997, fl., Rakotomalaza et al. 1275 ( MO) ; Fkt. Ampitambe, Ambatovy , env. 22 km NE de Moramaga , 18°51’24”S 48°18’39”E, 1082 m, 3.III.2005, fl., Rakotovao et al. 1466 ( MO, P) ; Fkt. Menalamba, 11 km E d’Ampitambe , Ambatovy , 18°49’26”S 48°20’02”E, 1081 m, 31.III.2005, fl., Rakotovao et al. 1694 ( MO, P) ; ibid. loc., 18°49’14”S 48°19’27”E, 1114 m, 4.IV.2005, fl., Rakotovao & Edmond 1766 ( MO, P) ; Fkt. Ampitabe, Ambatovy , coté W de la route vers Andranovery , 18°51’37”S 48°18’02”E, 1107 m, 21.V.2008, fl., Rakotovao 4056 ( MO, P) ; Fkt. Ampitambe, piste direction S du campement Dynatec , 18°51’26”S 48°18’12”E, 1080 m, 18.I.2005, fl., Ranaivojaona et al. 1133 ( MO, P) ; Analamazaotra, Amboasary , 18°57’07”S 48°25’53”E, 1040 m, 18.XII.2013, fl., Rasoazanany et al. 559 ( MO, P) ; Mantadia, boucle chute sacrée - Rinasoa , 18°49’48”S 48°26’25”E, 1074 m, 19.XII.2013, fl., Rasoazanany et al. 566 ( P) ; Fkt. Menalamba, forêt d’Ampangadiatrandraka , 18°51’15”S 48°17’52”E, 1110 m, 8.XII.2006, fl., Razanatsoa & Marcellin 255 ( MO, P).