Hornschuchia santosii D.M.Johnson

Vilela, Lucas & Lopes, Jenifer De Carvalho, 2022, Hornschuchia (Annonaceae), an endemic and threatened genus from the Brazilian Atlantic Forest, European Journal of Taxonomy 828, pp. 75-108 : 99-100

publication ID

https://doi.org/10.5852/ejt.2022.828.1859

DOI

https://doi.org/10.5281/zenodo.6828367

persistent identifier

https://treatment.plazi.org/id/03C887E4-011A-FFDB-FDE8-FD42FB147BE6

treatment provided by

Felipe

scientific name

Hornschuchia santosii D.M.Johnson
status

 

Hornschuchia santosii D.M.Johnson

Figs 4E View Fig , 6 View Fig

Brittonia 47 (3): 303, fig. 24 ( Johnson & Murray 1995).

Type: BRAZIL – Bahia • ( Teixeira de Freitas *) , “Km 6 da rod. Teixeira de Freitas a Alcobaça”; [17°31′05.6″ S, 39°39′07.3″ W]; 9 Oct. 1971; T.S. dos Santos 2091; holotype: CEPEC [ CEPEC00007576 View Materials ]!; isotype: NY [ NY00008357 ] GoogleMaps !.

Material examined

BRAZIL – Bahia • “Buerarema, Rodovia que liga Buerarema a Vila Brasil, km 14”; [15°03′40.9″ S, 39°14′28.1″W]; 9Feb.1982; A.M.de Carvalho 1172; CEPEC [ CEPEC00028511 View Materials ]!, HEPH [ HEPH00001089 View Materials ]!, NY [ NY00395773 ] GoogleMaps ! • ibid.; 9 Feb. 1982; A.M. de Carvalho 1175; CEPEC n.v., HEPH [ HEPH00001087 View Materials ] GoogleMaps ! • Canavieiras ” ( Santa Luzia *); 15º22′ S, 39º11′ W; alt. 100 m; 15 Aug. 1984; M.M. Santos 169; CEPEC [ CEPEC00037788 View Materials ] GoogleMaps ! • “ Santa Luzia, Vila São João . Reserva de mata do CEPLAC, entrada em bifurcação à direita da estrada Santa Luzia-Vila São João, 18, 5 km além do rio na saída de Santa Luzia, 4.6 km além da bifurcação e 1 km além de ponte de concreto da reserva”; 15º23′18.2″ S, 39º12′04.9″ W; alt. 97 m; 26 Oct. 2008; R. Mello-Silva et al. 3134; SPF GoogleMaps ! • Una ” ( Santa Luzia *), “Estrada de Una para Santa Luzia, ca 1 km após a Vila São João, ca 20 km de Una, ramal à esquerda”; 15º23′ S, 39º12′ W; 4 Dec. 2002; P. Fiaschi 1226; CEPEC [ CEPEC00094181 View Materials ]!, CEPEC00094205 View Materials ]!, NY [ NY01806300 ]!, RB [ RB00484635 ]!, SPF GoogleMaps !.

Description

Shrubs or trees, 2–7 m tall. Leaves chartaceous, petiole 1–5 mm long, lamina 8.6–20.5(–25.7) × 2.8– 9.8 cm, narrowly oblong to elliptic, narrowly obovate to oblanceolate or narrowly ovate, both surfaces glabrous, base cuneate, rounded to obtuse, apex attenuate to acute or obtuse, primary vein impressed adaxially and raised abaxially, 9–14 pairs of secondary veins, raised adaxially, angles between primary and secondary veins 40–60°. Inflorescence 4–12-flowered in highly ramified branches, axillary, terminal or leaf-opposed, bracts absent. Flowers with pedicel 2–25 mm long, flower buds 4–9 × 1.5–3 mm, conical with rounded apex, covered in trichomes. Sepals completely connate, calyx cupuliform, apex truncate, 1–3 × 3–5 mm, densely covered in trichomes. Petals linear, white, 9–22 mm long, covered in trichomes, stamens 6–18, 2–3.5 × 0.5 mm, carpels 2–9, 1–3 × 0.5 mm. Monocarps 1–3, globose to ovoid with rounded to acute apex, 21–22 × 16–19 mm, glabrous, stipe 1.5 mm long, calyx persistent. Seeds 6–8, 12–15 × 7–8 mm, flattened ellipsoid with aril.

Distribution and habitat

Hornschuchia santosii is endemic to Bahia, only known from three localities, the municipalities of Buerarema, Santa Luzia and Teixeira de Freitas. The only records in the municipalities of Canavieiras, Santos 169, and Una, Fiaschi 1226, have their geographic coordinates in Santa Luzia, in the same place of the collection Mello-Silva 3134. This region is close to the border of these three municipalities; therefore, it is possible that the collections Santos 169 and Fiaschi 1226 were made in Santa Luzia. The species inhabits lowland tropical moist forest ( Gouvêa et al. 1976; Thomas& Barbosa 2008; Fig. 6 View Fig ).

Phenology

Flowering from February to December, fruiting in December.

Preliminary conservations status

Hornschuchia santosii has an EOO of 1378 km 2 and an AOO of 12 km 2. It has been found at three localities, one of them in a conservation unit. It has not been collected in 10 years. Moreover, as already mentioned, the region H. santosii inhabits is endangered due to deforestation ( Landau et al. 2008). Therefore, it should be considered Endangered, EN B1ab(iii)+2ab(iii), according to IUCN Red List Categories and Criteria ( IUCN 2012).

Notes

Hornschuchia santosii is the only species with up to 18 stamens and 9 carpels, it is similar to H. obliqua , the note under the latter describes the differences between them.

Distribution, endemism and conservation

Hornschuchia is a threatened genus, 11 of its 12 species are classified either as Critically Endangered, Endangered or Vulnerable. Only H. bryothophe is categorized as of Least Concern following the IUCN criteria ( IUCN 2012) ( Table 1 View Table 1 ). We have inferred the conservation status of five species: H. citriodora , H. leptandra , H. linanarum , H. polyantha and H. santosii , all classified as Endangered. The remaining species have already been classified. One species is Critically Endangered, H. alba , nine species are Endangered: H. cauliflora , H. citriodora , H. leptandra , H. lianarum , H. mediterranea , H. mellosilvae , H. obliqua , H. polyantha and H. santosii , while one is Vulnerable, H. myrtillus ( Table 1 View Table 1 ).

Seven species are known from only five or fewer localities: H. citriodora , H. leptandra , H. lianarum , H. mediterranea , H. mellosilvae , H. obliqua and H. santosii ( Table 1 View Table 1 ). Four species have not been collected in more than 17 years: H. alba , H. leptandra , H. mellosilvae and H. obliqua . Only four species are found in conservation units: H. bryotrophe , H. citriodora , H. leptandra and H. myrtillus .

Hornschuchia is endemic to the Brazilian Atlantic Forest, as defined by law ( Brasil 2006), occurring from the State of Pernambuco to Rio de Janeiro ( Fig. 7A View Fig ). The species with the widest distribution is H. bryotrophe with a single collection in Pernambuco, its main distribution is from Bahia to Rio de Janeiro ( Fig. 1 View Fig ). One species is endemic to Rio de Janeiro, H. alba ( Fig. 1 View Fig ). Seven species are endemic to Bahia: H. cauliflora , H. leptandra , H. mediterranea , H. mellosilvae , H. polyantha , H. obliqua and H. santosii ( Figs 3 View Fig , 5–6 View Fig View Fig ). Most species occur in moist lowland tropical forest. Eight species also occur in seasonal semideciduous forest: H. alba , H. bryotrophe , H. cauliflora , H. leptandra , H. lianarum , H. mediterranea , H. mellosilvae and H. myrtillus ( Figs 1 View Fig , 3 View Fig , 5–6 View Fig View Fig ). Hornschuchia lianarum and H. mediterranea reach the seasonal deciduous forest of Bahia and are the only species occurring in this type of vegetation ( Figs 3 View Fig , 5 View Fig ).

Southern Bahia is the centre of species richness for Hornschuchia (8 spp.); followed by northern Bahia (4 spp.) and northern Espírito Santo (3 spp.; Fig. 7B View Fig ). Southern Bahia, the region close to Ilhéus, is also where most of the specimens have been collected, ranging from 13 to 18 records per cell ( Fig. 7C View Fig ). The second region where most of the species have been collected is Espírito Santo, close to Linhares, with eight records per cell ( Fig. 7C View Fig ).

The total points of occurrence for the species of Hornschuchia were 105. Two bioregions were identified, one including the coast of Bahia and northern Espírito Santo, bioregion 1; the other encompassing Rio de Janeiro and southern Espírito Santo, bioregion 2 ( Fig. 7D View Fig , Table 2 View Table 2 ). Nine species are the most indicative for bioregion 1: Hornschuchia bryotrophe , H. cauliflora , H. polyantha , H. leptandra , H. lianarum , H. mediterranea , H. mellosilvae , H. obliqua and H. santosii ( Table 2 View Table 2 , Fig. 7D View Fig ). In bioregion 2, the most indicative species are H. alba , H. citriodora and H. bryotrophe ( Table 2 View Table 2 , Fig. 7D View Fig ).

CEPEC

CEPEC, CEPLAC

NY

William and Lynda Steere Herbarium of the New York Botanical Garden

HEPH

Jardim Botânico de Brasília

SPF

Universidade de São Paulo

RB

Jardim Botânico do Rio de Janeiro