Hornschuchia mediterranea Mello-Silva & D.M. Johnson, 2021

Mello-Silva, Renato, Lopes, Jenifer De Carvalho & Johnson, David M., 2021, The new inland Hornschuchia mediterranea (Annonaceae) from Bahia, Brazil, Phytotaxa 483 (3), pp. 285-290 : 286-289

Hornschuchia mediterranea Mello-Silva & D.M. Johnson , spec. nov.

Type: — Brazil. Bahia: Jussari. Fazenda São Roque, 2,8 km em estrada vicinal à direita da estrada Jussari-Palmira, entrada a 13,8 km além da ponte sobre o rio Piabanha, na saída de Jussari (entrada à esquerda a 2 km de Palmira no sentido Palmira – Jussari), mata semidecidual de encosta, antropizada, elev. 211 m, 15 o 08’17.4”S 39 o 34’16.8”W, 28 October 2008, R. Mello-Silva, D. Y. A. C. Santos & J. C. Lopes 3138 (holotype, SPF 3 sheets!; isotypes, CEPEC!, K!, NY!, OWU!, RB!, W!). Figures 1A – D , 2 .

Species floribus solitariis ex internodiis exorientibus, calyce profunde cupulato necnon habitatione H. lianis simulans, sed foliis ellipticis glabris nitidisque, plerumque maioribus, nervis secundariis superne plerumque leviter impressis, indumento calycis sericeo, petalisque albis libris jam in alabastris, et staminibus tribus aut sex distinguitur.

Treelet 2 – 8 m tall, leaf-bearing twigs glabrous, blackish, older branches greyish, leaf-buds densely covered with grey to brownish appressed hairs. Lamina of larger leaves (5–)7.4 – 15 × 2 – 7 cm, subcoriaceous to chartaceous, elliptic to ovate, shiny, discolorous, base cuneate to broadly cuneate, very slightly asymmetric; apex slightly to distinctly acuminate, acumen 5 – 20 mm long; adaxial surface glabrous, light olive, abaxial surface light yellowish-olive, initially sparsely covered with appressed hairs, at length with few hairs persistent mostly on the midrib; midrib impressed adaxially, raised abaxially, secondary veins 7 – 10 per side, departing at ca. 60 o from the midrib, flat to slightly raised on adaxial surface, raised on abaxial surface, as are the higher-order veins. Petiole 2 – 4 × 1 – 2 mm, indument as on the lamina. Flowers solitary, internodal on leafy new shoots; pedicel 4 – 6 × 1 – 1.5 mm, covered with olive to greyish appressed hairs; young flower buds ovoid, becoming cylindrical. Calyx 3 – 6.5 × 4 – 7 mm, deeply cup-shaped, apex almost truncate, sometimes with distinct, shallowly triangular, obtuse lobes 1.8 – 2.2 × ca. 3 mm, covered with fine olive to greyish appressed hairs abaxially. Corolla white (even in bud); petals of both whorls 6 – 9 × 1.5 – 2 mm at base, the inner petals sometimes shorter than the outer petals, free, oblong-lanceolate, obtuse at apex, adaxially glabrous, outer petals flat, abaxially covered with olive to greyish appressed hairs, inner petals triangular in cross-section, with a median strip of olive to greyish appressed hairs abaxially but otherwise glabrous. Stamens 3 – 6, 2 – 3 × ca. 1 mm, oblong, apex of connective conical, not overhanging the anther locules. Carpels 5 – 8; ovaries 2 – 3 mm long, ovoid, densely covered with olive to greyish appressed hairs; ovules ca. 8, in two rows; style 1.5 – 2 mm long, glabrous; stigma ca. 0.2 mm long, linear. Torus ca. 1.5 mm in diam. Fruit composed of 2 – 5 monocarps borne on a pedicel 3.5 – 10 × ca. 2 mm; monocarps 8 – 13 × 5 – 9 mm, globose to ovoid, rugose, densely velutinous, sessile, apex slightly apiculate; wall ca. 1 mm thick. Seeds 3 – 4, 7 – 7.2 × ca. 4 mm, obovoid to ellipsoid, rugulose, light brown, caruncule trapeziform, convolute.

Distribution and Habitat ( Figure 3 ):— Hornschuchia mediterranea occurs in seasonal semideciduous forests of the Brazilian state of Bahia, in the municipalities of Jussari and Antônio Cardoso, ca. 60 km inland from the coast, and in Mundo Novo, ca. 230 km inland, also in semideciduous forests but where the climate is influenced by the nearby Espinhaço range of mountains, at elevations of 155 – 465 meters.

Conservation status:— Hornschuchia mediterranea has an Extent of Occurrence of 24,664 km 2, and an Area of Occupancy of 16 km 2. Based on this assessment, its conservation status could be interpreted as Endangered, EN B 2ab(iii), according to IUCN Red List Categories and Criteria (2012), as the populations inhabit very threatened forests.

Etymology:— mediterranea , from Latin, medius (middle) plus terra (land), meaning inland, in the middle of the land, remote from the sea ( Stearn 1983).

Phenology:—Specimens with buds and flowers were gathered from February to April, and with buds and fruits in August and October.

Notes:— Hornschuchia mediterranea resembles H. lianarum , from Bahia and northern Minas Gerais (Mello-Silva 3140, SPF, Figure 1E – F ), which similarly occurs in inland semideciduous forests. Besides inhabiting similar habitats, the two species share the solitary, internodal flowers with a deeply cup-shaped calyx. Characteristics of H. lianarum that distinguish it from H. mediterranea are the pubescent, ovate to broadly ovate and generally smaller leaf lamina with secondary veins slightly raised on both surfaces, and petals connate and orange-cream in bud. Hornschuchia mediterranea also resembles H. alba . These two species share solitary and internodal flowers, free petals that are white even in bud, and glabrous, shiny leaves. The main differences between the two species lie in floral characters: Hornschuchia mediterranea has a calyx 3 – 6 mm long and 4 – 7 mm in diameter, three to six stamens, and five to eight carpels, while H. alba has a calyx 1 – 3 mm long and 2 – 3 mm in diameter, six stamens, and three carpels. In addition, they inhabit quite different types of Atlantic Forest, compared to the other species of Hornschuchia (e.g. Bertoncello et al. 2011). Apart from these three species, only H. obliqua Maas & Setten in Maas et al. (1988: 260) shows a deeply cup-shaped calyx, but it has numerous flowers on supra-axillary to terminal branched rhipidia, and inhabits tropical moist forests. The variable number of stamens is also a notable attribute of H. mediterranea , as almost all other species of the genus present six stamens, except H. santosii D.M.Johnson in Johnson & Murray (1995: 303), with six to 18 stamens, and H. cauliflora Maas & Setten in Maas et al. (1988: 259), which, like H. mediterranea , shows three or six stamens. Such floral reduction is remarkable within the entire family Annonaceae ( Johnson & Murray 1995) .

Additional specimens examined:— BRAZIL. Bahia: Antônio Cardoso. Fazenda Sossego, mata semidecídua antropizada, elev. 155 m, 12 o 21’56”S 39 o 06’33”W, 11 August 1999, E . Melo , F. França, E . Miranda, L . Senna & B. M . Silva 2774 ( HUEFS, SPF); Mundo Novo. Entrada para a cidade, próximo à rodovia BA 052 ( Estrada do Feijão ) , elev. 465 m, 11 o 52’35”S 40 o 27’09”W, 11 August 1999, E . Melo , F. França, E . Miranda, L . Senna & B. M . Silva 2784 ( HUEFS, SPF); Jussari. Ca. 2.5 km N of Palmira on road connecting Palmira to the Itaju do Colônia – Itapé road, fazenda São Roque, transitional sub-deciduous forest, some of it disturbed, elev. 300 – 450 m, 15 o 08.3’S 39 o 34.3’W, 2 February 1999, W. W . Thomas, J. A . Kallunki & J. G . Jardim 11935 ( CEPEC not seen, NY, OWU, SPF); ca. 2.5 km N of Palmira on road connecting Palmira to the Itaju do Colônia – Itapé road, fazenda São Roque , transitional sub-deciduous forest, some of it disturbed, southern Bahia mesophyllous forest, elev. 250 – 300 m, 15 o 08.476’S 39 o 34.749’W, 14 March 2001, W. W . Thomas, H. M . Longhi-Wagner & S . Sant’Ana 12313 ( CEPEC, HUEFS, MBML, NY, OWU, SPF, UFRN); fazenda Serra do Teimoso, reserva Serra do Teimoso , lower forest, northern portion of reserva, elev. 275 – 350 m, 15 o 09’12”S 39 o 31’50”W, 16 March 2003, W. W . Thomas, A. M . Amorim, S . Sant’Ana, J. L . Paixão & R. N . Querino 13393 ( CEPEC, NY, SPF) .

In Memoriam: We honor our colleague, teacher, and friend Renato de Mello-Silva for his contributions to Brazilian floristics and plant taxonomy, especially of the families Annonaceae and Velloziaceae . He was an accomplished field botanist, who loved to collect plants in different parts of Brazil, a dedicated curator of the herbarium at SPF, and an excellent teacher, helping to train many Brazilian botanists. He will be greatly missed.

Figures

FIGURE 1. A–D. Hornschuchia mediterranea. A. Habit (Mello-Silva et al. 3138). B. Shoot with buds and an old flower (Mello-Silva et al. 3138). C. Fruiting branch (Mello-Silva et al. 3138). D. Flower (Thomas et al. 12313). E–F. Hornschuchia lianarum (Mello-Silva et al. 3140). E. Shoot with flower buds. F. Leaves, showing raised venation.

FIGURE 2. Hornschuchia mediterranea. A. Flower, longitudinal section showing stamens and carpels. B. Flowering branch. C. Flower, side view. D. Stamen, abaxial view. E. Monocarp. F. Seed, longitudinal view. A, B, based on Thomas 13393 (NY, SPF), C, based on Thomas 12313 (OWU), D, F, based on Melo et al. 2784 (SPF), E, based on Thomas 11935 (NY). Illustration by Kate Stenger, A, D, F, based on original drawings by Laura Montserrat.

FIGURE 3. Distribution map of Hornschuchia mediterranea (black dots) in the Brazilian state of Bahia. Shape files with South American and Brazilian political divisions were downloaded from http://www.forest-gis.com/download-de-shapefiles/.