Bernardia hamadryadica J.F. Carrión & Cordeiro, 2017

Carrión, Juan F., Cordeiro, Inês & Amorim, André Márcio, 2017, A new species of Bernardia (Euphorbiaceae) from the Chapada Diamantina, Bahia State, Brazil, Phytotaxa 317 (1), pp. 69-75 : 70-74

Bernardia hamadryadica J.F. Carrión & Cordeiro , sp. nov. ( Figs.1–3 )

Type: — BRAZIL. Bahia: Mun. Morro do Chapéu. Exterior do Buraco do Possidônio. Acesso pela estrada para Bonito (1 km de estrada de asfalto), entrada à direita (16 km em estrada de cascalho), estrada à esquerda passando por uma cancela (0,6 km). 11º38’50.1”S, 41º16’10.6”W, elev. 970 m, 1 December 2016, staminate fl., J.F. Carrión & R.G. Barbosa-Silva 1730 (holotype HUEFS!, isotypes ALCB!, CEPEC!, K!, MO!, NY!, RB!, SP!).

Diagnosis: — Bernardia hamadryadica can be recognized by the combination of its shrubby habit, inflorescences and young leaves usually produced on short shoots, membranaceous leaf laminas less than 6 cm long, with disk-shaped and slightly prominent glands on the abaxial surface, spiciform staminate inflorescence, up to 1 cm long, entire style branches, and indumentum of simple trichomes.

Description: —Dioecious shrubs, 0.3–3 m tall, much-branched; branches scarcely striate, young parts covered by a dense indumentum of simple trichomes. Leaves alternate, scattered along the branches and congested on the reproductive, short lateral shoots; lamina membranaceous, obovate to elliptic, 1.2–5.8 × 0.6–2.5 cm; discolorous; base attenuate; margin serrate, basally sub-entire, with an ovoid gland and sometimes with a tuft of simple trichomes at the tip of each tooth; apex obtuse to acute; abaxial surface densely pubescent, adaxial surface puberulous; disk-shaped glands 1–5, present on the abaxial surface, slightly prominent, usually 1 gland on both sides of the midvein, close to the lamina base, sometimes reddish; venation palmati-pinnate, secondary veins in 5–7 pairs, intersecondary veins percurrent. Stipules 2–5 mm long, linear-lanceolate, slightly concave, acuminate, rigid, thickened, pubescent, pale yellow, persistent after the leaf falls, 1–4 pairs at the base of shoots; petiole 3–6 mm long, densely pubescent. Staminate inflorescence axillary, spiciform, 0.3–1 cm long at anthesis, sessile to short pedunculate, peduncle up to 3 mm long, erect, densely pubescent; 2–5 bracts loosely scattered or congested along the axis, concave, apex acute, 1–2.7 mm long, pale yellow, thickened, both surfaces pubescent; each bract subtending cymes of 4–10 flowers; bracteoles linear to lanceolate, 0.5–1 mm long, pubescent. Staminate flowers pedicellate, usually conspicuously exserted at anthesis, pedicel articulate, 1–5 mm long; sepals 3–4, valvate, obovate, 0.8–1.4 × 0.6–1 mm, hyphodromous, outer surface densely pubescent, inner surface glabrous, margins ciliate; stamens 6–8; filaments 0.5–1 mm long, anthers 0.1–0.2 mm long; interstaminal disk of 5–8 shortly stalked, reddish segments. Pistillate flowers solitary or in a glomeruliform cyme, terminal or axillary, sometimes pedunculate, peduncle to 5 mm long; bracts 3–4, ovate, slightly concave, unequal in size and shape, 1–3 × 1.5–2 mm, apex acute; flowers sessile or pedicellate, the pedicel up to 2 mm long; sepals 5–6, ovate, persistent, 2.5–3 × 1.5–2 mm, hyphodromous, outer surface pubescent, inner surface glabrous; disk annular; ovary globose, densely pubescent; styles 3(–4), bifid, recurved, 1.5–2 mm long, branches to 3 mm, entire, verrucose, covered with sparse simple trichomes. Fruits globose, trilobed, 6–10 × 7–12 mm, green when mature, exocarp slightly verrucose, densely pubescent, stigma and calyx persistent; sometimes pedicellate, pedicel 2–8 mm long; columella 3–5 mm long, trilobed, persistent. Seeds 6–7 × 4–5 mm, carinate, cordiform in ventral view, smooth, shiny, brown/brownmarbled.

Taxonomic notes: —According to the most recent taxonomic revision of Bernardia (Pax & Hoffman 1914) , Bernardia hamadryadica would be classified within Bernardia sect. Polyboea Müller Argoviensis (1865: 173) . However, the new species differs from the others of the section by the combination of the following: short shoots bearing young leaves and inflorescences, which elongate later; membranaceous leaf lamina, less than 6 cm long, with slightly prominent disk-shaped glands along the abaxial surface, which differ from the embedded pattern of the laminar glands found in the genus; spiciform staminate inflorescences, equal to or less than 1 cm long; and fruits sometimes pedicellate.

In Bernardia , the presence of short shoots is only known for some species of Bernardia sect. Bernardia from arid regions of North America; however, these taxa have an indumentum of stellate-fasciculate trichomes and lacinulatelacerate style branches ( Cervantes 2006).

Within section Polyboea , relatively small leaves, short staminate inflorescences, and pedicellate fruits are also present in Bernardia similis Pax & Hoffman (1914: 35) . However, B. similis has coriaceous leaves, embedded disk-shaped glands on the abaxial surface of the lamina, and subsessile staminate flowers in subglobose inflorescences (vs membranaceous leaves, slightly prominent disk-shaped glands on the abaxial surface of the lamina, and conspicuously pedicellate staminate flowers in spiciform inflorescences in B. hamadryadica ). In addition, B. similis occurs in campo rupestre (rocky fields) and cerrado (savanna) vegetation in the southern Espinhaço Range in Minas Gerais State, within the Cerrado phytogeographic domain. In contrast, B. hamadryadica occurs in cerradão (forest savanna) and seasonally dry tropical forests, such as caatinga and mata seca vegetation, in the northern Espinhaço Range in Bahia State, within the Caatinga phytogeographic domain.

Additional specimens examined (paratypes): — BRAZIL. Bahia: Mun. Morro do Chapéu, Buraco do Possidônio , 11º38’47”S, 41º16’11”W, elev. 960 m, 17 April 2008, pistillate fl. and fr., E. Melo et al. 5506 (HUEFS!, SP!) ; ibid., staminate fl., E. Melo et al. 5512 (HUEFS!, SP!) ; ibid., exterior do Buraco do Possidônio , 11º38’50.1”S, 41º16’10.6”W, elev. 970 m, 1 December 2016, pistillate fl. and fr., J.F. Carrión & R.G. Barbosa-Silva 1731 (CEPEC!, HUEFS!, K!, RB!, SP!) ; Mun. Rio de Contas, Serra do Rio de Contas, proximidades de Boa Sentença, Morro da Morceguinha , 13º49’34”S, 41º35’4”W, 5 December 2004, staminate fl., R.M. Harley et al. 55283 (HUEFS!) ; Mun. Barra do Mendes, ca. 17.5 km do povoado de São Bento, estrada para Torre , 11º48’25”S, 42º11’17”W, elev. 800 m, 17 December 2009, pistillate fl. and fr., E. Melo et al. 7662 (HUEFS!) .

Distribution, habitat and phenology: — Bernardia hamadryadica is only known from the Morro do Chapéu, Rio de Contas and Barra do Mendes municipalities in the state of Bahia, northeastern Brazil ( Fig. 3 ), where it occurs above 800 m elevation on limestone outcrops, quartzite rocks and metamorphic sandstone soils. This species is found in caatinga, mata seca (seasonally dry tropical forests) and cerradão (forest savanna) vegetation, which are phytophysiognomies composed mostly of small trees and shrubs that frequently have twisted trunks, thorns, and other xerophytic characteristics. It was found in flower and fruit in April and December.

Etymology: —The specific epithet refers to the phytogeographic province “Hamadryas” proposed by the German botanist and explorer Carl Friedrich Philipp von Martius to designate the dry vegetation of northeastern Brazil (which is currently called caatinga), where most populations of the new species occur.

Conservation: — Bernardia hamadryadica has been documented from only three localities, which are not in conservation units. Therefore, it may be subjected to disturbance and habitat deterioration, as it is happening in the type locality (“Buraco do Possidônio” in the Morro do Chapéu municipality) where palm ( Arecaceae ) crops very close to the new species population were observed. Thus, following IUCN Red List categories and criteria ( IUCN 2017), the extent of occurrence (EOO) of 11,838.616 km ² and area of occupancy (AOO; grid cell area of 2 km ²) of 12.000 km ² lead us to classify Bernardia hamadryadica as endangered (EN B2 ab[ii,iii,iv]).

Figures

FIGURE 1. Bernardia hamadryadica. A) Staminate branch; B) Detail of petiole and stipules; C) Abaxial leaf surface showing vein pattern, indumentum and slightly prominent disk-shaped glands; D) Staminate inflorescence; E) Staminate flower; F) Bract of staminate flower; G) Fruiting branch; H) Detail of leaf lamina margin with gland at the tip of the teeth; I) Pistillate flower; J) Bract of staminate flower; K) Gynoecium; L) Fruits; M) Seeds in dorsal, lateral and ventral views. Drawings by Klei Sousa, A–F based on J.F. Carrión 1730 and G–M based on J.F. Carrión 1731.

FIGURE 2. Bernardia hamadryadica. A) Habit; B) Staminate short branches; C) Abaxial leaf surface; D) Staminate inflorescences; E) Pistillate inflorescence; F) Fruits; G) Caatinga vegetation from the type locality. Photos A, B, E and F by J.F. Carrión; C, D and G by Rafael Gomes.

FIGURE 3. Geographical distribution of Bernardia hamadryadica (black circles) in the Chapada Diamantina, northern extension of the Espinhaço Range (dark gray area).