Noronhia broomeana Horne ex Oliv.

Hong-Wa, Cynthia, 2016, A taxonomic revision of the genus Noronhia Stadtm. ex Thouars (Oleaceae) in Madagascar and the Comoro Islands, Boissiera 70, pp. 1-292 : 56-57

8. Noronhia broomeana Horne ex Oliv. in Hooker’s Icon. Pl. 14: tab. 1365. 1881.

≡ Linociera broomeana (Horne ex Oliv.) Knobl. in Notizbl. Bot. Gart. Berlin 11: 1028. 1934.

≡ Chionanthus broomeana (Horne ex Oliv.) A.J. Scott in Kew Bull. 33: 570. 1979.

Typus: M AURITIUS: Forests near Grand Bassin, [20°25’S 57°29’E], s.d., Horne s.n. (holo-: K [ K000233208 ] image seen) .

= Linociera verrucosa Soler. in Bot. Centralbl. 45: 399. 1891. ≡ Mayepea verrucosa (Soler.) Knobl. in Engler, Nat. Pflanzenfam. 4: 10. 1892. Typus: M AURITIUS: sine loc., s.d., Sieber 125 (holo-: M [ M0174392 ] image seen; iso-: E [ E00193166 ] image seen, G [ G00008578 ] image seen, K [ K000233210 ] image seen, MO [ MO2235287 ]!).

= Linociera mayottensis H. Perrier in Mém. Inst. Sci. Madagascar, Sér. B, Biol. Vég. 2: 280. 1949 .

≡ Noronhia mayottensis (H. Perrier) Hong-Wa & Besnard in Mol. Phylogenet. Evol. 67: 376. 2013. Typus: M AYOTTE: sine loc., between 1847 and 1852, Boivin 3196 (holo-: P [ P00184542 ]!) .

Description

Trees to 8 m tall; young twigs subquadrangular, 1.3-2.6 mm diameter, pubescent to glabrous at maturity; bark dark to medium gray, slightly rugose, with scattered lenticels. Leaves opposite, persistent; bud scales rarely persistent; blades light green to yellowish above and below, oblong, 6.5-12 3 2.5-5.5 cm, chartaceous, pubescent to glabrous at maturity, domatia casual, base acute, margin flat, apex acute to acuminate, the acumen 2-8 mm long, midrib flat above and distinctly raised below, secondary veins conspicuous, 8-10 per side, 8-17 mm apart, looping 2-6 mm from the margin; petiole yellowish to reddish, 6-13 3 1-1.5 mm, not woody, glabrous. Thyrses fasciculate, multiflorous, compact; peduncle 5-18 mm long, densely pubescent; pedicel 1-4 mm long, densely pubescent; calyx densely pubescent outside, glabrous inside, lobes triangular, 1.5 3 1.2-1.5 mm; corolla white, rotate, petals almost free, 5-6 mm long, glabrous on both sides, the tube 1 mm long, lobes oblong, apex obtuse; corona absent; stamens 3.5-3.8 mm long, anthers elongate, apiculate, 2.8 mm long; pistil 2.6 mm long, stigma bilobed. Fruiting pedicel 3-4 3 1.5-2 mm; young fruits green, dark brown when mature, ovoid, 22 3 9 mm, surface ribbed, apex rostellate, the rostellum flattened, ridged, apiculate; dry pericarp 0.4 mm thick; endocarp woody; seed 18 3 7 mm.

Distribution, ecology and phenology

Noronhia broomeana occurs in low- to mid-elevation forests in Mascarene ( Réunion and Mauritius) islands ( Fig. 3 ) and possibly also in the Comoro islands (see notes). It produces flowers and fruits from November to March.

Conservation status

Noronhia broomeana has not been evaluated using the IUCN criteria in the Comoros and is assigned a preliminary status of “Not Evaluated”, although it appears to have a restricted distribution there and is very likely threatened. It is also possible that the species has been extirpated from the Comoros since it is known only there from a single collection made more than 150 years ago or that it has never occurred there, as discussed below. It has been evaluated as “Endangered” in Mauritius (HONG- WA et al., 2014) and as “Vulnerable” in Réunion (UICN-FRANCE et al., 2010).

Notes

Noronhia broomeana can be recognized by its chartaceous, somewhat pubescent leaf blades, white flowers with almost free petals, and slightly ribbed fruits. Noronhia mayottensis (H. Perrier) Hong-Wa & Besnard, a doubtful species from the Comoros described and recognized by PERRIER DE LA BâTHIE (1949, 1952) as Chionanthus (ex Linociera ) mayottensis , is here included within Noronhia broomeana , which extends the range of the latter to this archipelago. Although N. mayottensis was accepted earlier (HONG- WA & BESNARD, 2013), this actually resulted from a systematic transfer of all names in Chionanthus to Noronhia for species from Africa and the Indian Ocean Islands based on phylogenetic results that found them to be embedded within Noronhia (HONG- WA & BESNARD, 2013). The study of N. broomeana in Mauritius (HONG- WA et al., 2014) along with the examination of other material from Réunion allows the inclusion of N. mayottensis within this group. To my knowledge, no other collection assignable to N. mayottensis is available from the Comoros, raising the question as to whether Boivin actually collected it there. In any case, the morphological characteristics of this specimen fit well with those of N. broomeana across its geographic range.

Additional specimens examined

MAURITIUS: s.d., Bouton s.n. ( MAU) ; Rivulet Bois Beau , near Rivière des Anguilles, 193 m, 20°27’57’’S 57°33’25’’E, 17. V.2010, V. Florens & Baider CB 2367 ( MAU) ; Bassin Blanc , 550 m, 25. V.1976, Richardson 4165 ( K, MAU) . RéUNION: Ile Bourbon, 1848, Boivin 1209 ( P) ; Cirque de Hellbourg , Le Bélier, Sentier d’Aurère, 31.X.1972, Bosser 21444 ( P) ; Dos d’Ane, 650 m, II.1972, Friedmann 1608 ( P) ; Grand Coude , 900 m, III.1972, Friedmann 1652 ( P) ; Grande Chaloupe , 400 m, XI.1972, Friedmann 1950 ( P) ; Salazie , 1200 m, XII.1972, Friedmann 2028 ( P) ; Mare Longue , St. Philippe, III.1974, Friedmann 2316 ( MO, P) ; Cape Noire (Mafate), 10.III.1977, Friedmann 3079 ( P) ; Mare Longue , St. Phillipe, 200 m, 16.XI.1966, Schlieben 10943 ( MO) ; Dos d’Ane, 9.XI.1968, Service Forestier 28246 ( P) .

Figures

Fig. 3. Distribution maps of species of Noronhia Stadtm. ex Thouars: N. alleizettei Dubard to N. capuronii Bosser.