Xylopia ravelonarivoi D. M. Johnson & N. A. Murray 2020, sp. nov.
Creators: name: Johnson, David M.
name: Murray, Nancy A.
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Magnoliales
Annonaceae
Xylopia
Xylopia ravelonarivoi

description: 7. Xylopia ravelonarivoi D.M.Johnson & N.A.Murray, sp. nov. (Figs 6B; 11)
Species resembling Xylopia humblotiana Baill. in its small blunt coriaceous leaves, obtuse petals, and narrowly oblong monocarps, but differing in the tree habit, more strongly decurrent leaf bases, densely pubescent pedicels and sepals, lanceolate outer petals, and more strongly wrinkled monocarps borne on pedicels 13-19 mm long and 1.6-3.7 mm thick.
TYPE. — Madagascar. Prov. Toamasina, Antsimanana Region: Brickaville, Maroseranana, Ambodilendemy, suivant la rivière d’Andrangato, 18°26’05”S, 48°46’51”E, 658 m, 14.III.2011 (fl.), Ravelonarivo et al. 3641 (holo-, MO!).
PARATYPES. — Madagascar. Prov. Antsiranana, Sava Region, Diego, Sambava, Anjangoveratra, Anamboafo, forêt de Makirovana-Beraharaha, 14°09’07”S, 49°57’13”E, 549 m, 6.III.2014 (fl.), Martial et al. 548 (MO); Sava Region, Sambava, Anjangoveratra, Anamboafo, forêt de Belalitra, Makirovana, 14°09’14”S, 49°58’09”E, 585 m, 8.III.2014 (fl.), Rakotonirina et al. 537 (MO); Marojejy RNI, Analamboahangy, Andrakata, Andapa, aux environs de Manenobasy, 14°35’16”S, 49°41’20”E, 1171 m, 18-24.I.1995 (fr.), Rasoavimbahoaka 509 (MO, P[P01954048]); Andrakata Canton, Andapa District [14°37’S, 49°43’E], 13.VIII.1957 (fr.), Safy 9089 RN (P[P01954046]).
Prov. Mahajanga, Ruisseau Ambatoharanana Andranomena commune rurale de Matsoandakana, district de Befandrina Nord, 15°08’16”S, 49°21’02”E, 1045 m, 12.II.2008 (fr.), Bernard et al. 778 (K, MO). Prov. Toamasina, Fivondronana Maroantsetra, Commune Ambinanitelo, Fokontany Marovovonana, Ankiriandro Mountain, 15°17’37”S, 49°33’10”E, 640 m, 10.I.2003 (fr.), Antilahimena et al. 1683 (K, P [P01954047]); Analanjirofo Region, Fivondronana Vavatenina, Commune Ambodimangavalo, à 3 km à l’Ouest du village Ambatoharanana, dans le Parc national de Zahamena, le long de la piste vers Antevibe, 17°33’54”S, 48°53’18”E, 875 m, 29.IV.2003 (fr.), Rakotonandrasana 676 (OWU); Toamasina sous-préfecture, Vavatenina, commune: Ambodimangavelo, Moango, dans l’Aire protégée de Zahamena, 17°33’32”S, 48°53’55”E, 800 m, 4.V.2003 (immature fr.), Rakotondrajaona et al. 281 (K, MO); Antsinanana Region, Vohimanana, Dist. Brickaville, Com. Maroseranana, Fkt. Ambatolampy, 18°23’27”S, 48°48’11”E, 846 m, 23.I.2012 (fr.), Ravelonarivo et al. 4171 (MO).
DISTRIBUTION, ECOLOGY AND CONSERVATION STATUS. — Xylopia ravelonarivoi, sp. nov., occurs in humid lowland and lower montane forest on ridges and slopes in northeastern Madagascar at elevations from 549 to 1171 meters.Specimens have been collected with flowers in March and with fruits in January, February, April, and May. With an EOO and AOO estimated as 7118 km 2 and 40 km 2, respectively, the species is given a preliminary conservation assessment of Endangered. It is documented by two collections from within the protected area of Zahamena National Park and one collection from the Marojejy Reserve.
LOCAL NAMES. — Hazoambo (Rakotondrajaona et al. 281), hazoambo boriboriravina (Rakotonandrasana 676), moranga (Martial et al. 548), morango (Rakotonirina et al. 537).
DESCRIPTION
Tree up to 15 m tall, or rarely a shrub up to 8 m; d.b.h. up to 30 cm.
Twigs densely appressed-pubescent, the hairs 0.1-0.3 mm long, eventually glabrate; nodes with one axillary branch.
Leaves with larger blades 5.0- 7.2 cm long, 2.0- 3.4 cm wide, subcoriaceous to coriaceous, discolorous, dark brown to gray and often shiny adaxially, light brown and dull abaxially, obovate, oblanceolate, elliptic, or elliptic-oblong, apex obtuse, rounded, retuse, or emarginate, base cuneate, decurrent on petiole, margin slightly recurved or revolute, glabrous adaxially, sparsely appressed-pubescent, especially along midrib, abaxially; midrib dull red to brown, darkening toward base adaxially, secondary veins weakly brochidodromous, 8-11 per side, diverging at 50-70° from midrib, these and higherorder veins raised and forming a conspicuous reticulum on both surfaces; petiole 1.5-7 mm long, shallowly canaliculate or a little flattened, smooth or faintly wrinkled, glabrous or with a few hairs.
Inflorescences axillary from the axils of fallen leaves, 1-3-flowered, pedunculate, densely appressed-pubescent; peduncle 1.7-1.8 mm long; pedicels up to 3 per peduncle, 4.8-9.7 mm long, 1.0- 1.2 mm thick; bracts 2, one near base of the pedicel and the other near midpoint, caducous, only scars seen; buds lanceolate, apex obtuse.
Sepals spreading at anthesis, ¼-1/2-connate, 1.4-3.6 mm long, 3.5-4 mm wide, coriaceous, broadly triangular, apex acute or rarely obtuse, appressed-pubescent abaxially.
Petals greenish white in vivo; outer petals slightly spreading at anthesis, 10.0- 12.2 mm long, 2.7-4.5 mm wide at base, 2.4-3.0 mm wide at midpoint, fleshy, lanceolate, keeled at the apex but otherwise flat adaxially, flat abaxially, apex obtuse, densely pubescent except for glabrous base adaxially, densely appressed-pubescent abaxially; inner petals slightly spreading at anthesis, 10.5-10.9 mm long, 2.2-3.0 mm wide at base, 0.9-1.2 mm wide at midpoint, fleshy, linear-subulate, keeled on both surfaces, apex acute, concave with undifferentiated margin, densely pubescent on both surfaces except for glabrous base, with a band of papillae across widest point adaxially.
Stamens c. 250; fertile stamens 1.1-1.4 mm long, narrowly oblong, anther connective apex 0.2-0.3 mm long, shield-shaped to capitate, overhanging anther thecae, minutely papillate, anthers 7-9-locellate, filament 0.4-0.6 mm long; outer staminodes c. 1.3 mm long, oblong to clavate, apex truncate or rounded; inner staminodes 1.0- 1.1 mm long, clavate, apex truncate; staminal cone 2.2-2.6 mm in diameter, 1.0- 1.5 mm high, completely concealing the ovaries, rim even.
Carpels 10-13; ovaries 1.0- 1.1 mm long, narrowly oblong, pubescent, stigmas connivent, 1.8-2.2 mm long, filiform, glabrous or with a few apical hairs.
Fruit of up to 13 monocarps borne on a pedicel 13-19 mm long, 1.6-3.7 mm thick, glabrate or with a few scattered hairs; torus 5-12 mm in diameter, 3.5-9 mm high, depressed-globose; monocarps with red exterior in vivo, 2.2-4.5 cm long, 0.5-0.9 cm wide, 0.5-0.8 cm thick, narrowly oblong, often slightly torulose, apex obtuse to rounded, sometimes slightly beaked, base tapered gradually, sometimes forming a stipe c. 4 mm long, 3 mm thick, obliquely wrinkled, shiny, glabrate; pericarp 0.3-0.8 mm thick.
Seeds up to 5 per monocarp, in a single row, nearly parallel to long axis, 5.6-7.8 mm long, 2.9-4.6 mm wide, 3.3-4.0 mm thick, broadly ellipsoid to oblong, elliptic in cross-section, dark brown to black, smooth or slightly wrinkled and pitted, shiny, perichalazal ring slightly raised; sarcotesta absent; aril white in vivo, white to amber-colored when dried, bilobed, lobes 2.0- 2.5 mm long, 3.0- 3.6 mm wide, fleshy, surface wrinkled.
NOTES
Xylopia ravelonarivoi, sp. nov., is similar to X. humblotiana but differs in a number of characters that, together with the ecological differences, distinguish the two species. It is usually a tree up to 15 m tall, rather than a shrub or treelet. The leaves have a more decurrent base, such that the demarcation between blade and petiole is indistinct (Fig. 11B). The pedicels and sepals are densely pubescent. The sepals are longer, and the outer petals are lanceolate rather than oblong; the latter character is also expressed in the buds that are lanceolate rather than oblong as in X. humblotiana. The monocarps of this species are obliquely wrinkled, while those of X. humblotiana are usually smooth. There is a sharp difference in elevation range between the two species: X. ravelonarivoi, sp. nov., grows at elevations from 550 to 1170 m and X. humblotiana from sea level to 50 m. Xylopia madagascariensis also has monocarp and leaf sizes similar to those of X. ravelonarivoi, sp. nov., but its leaves are blunt- acuminate rather than obtuse to rounded and its monocarps are smooth and finely verrucose rather than strongly wrinkled. In addition, X. madagascariensis reaches its upper elevational limit at just over 500 meters, while the lower elevational limit for X. ravelonarivoi, sp. nov., is c. 550 meters.
The specimen Rakotondrajaona et al. 281 was the source of molecular data used in the phylogenetic analysis of Xylopia by Stull et al. (2017), where it was identified as X. humblotiana; the seed illustrated in Figure 4H of that work is, however, correctly identified as X. humblotiana.
The species is named for Désiré Ravelonarivo, the collector of the type specimen, who has contributed to a clearer understanding of Xylopia diversity on Madagascar by making 16 critical Xylopia collections representing six species.
description: Published as part of Johnson, David M. & Murray, Nancy A., 2020, A revision of Xylopia L. (Annonaceae): the species of Madagascar and the Mascarene islands, pp. 1-88 in Adansonia 42 (1) on pages 32-34, DOI: 10.5252/adansonia2020v42a1, http://zenodo.org/record/3877215