Pombalia barbata Paula-Souza, 2015

Paula-Souza, Juliana De & Souza, Vinicius Castro, 2015, Pombalia barbata, a new species of Violaceae endemic to the Brazilian Caatinga, Phytotaxa 218 (1), pp. 91-96 : 93-95

Pombalia barbata Paula-Souza , sp. nov. ( Figs. 1 , 2 , Table 1)

Species habitu cum P. attenuata (Humb. & Bonpl. ex Willd.) Paula-Souza optime congruens, a quo stylo barbato et sepalo ciliato-tomentoso differt. A P. communis habitu herbaceo et glandula stamine noduliformi etiam distincta.

TYPE: — BRAZIL. Bahia: Iaçu, Fazenda Santo Antônio, entrando pela rodovia Iaçu-Milagres , lajedo na caatinga, elev. 280m, 12º48’25”S, 40º05’51”W, 05 Feb 2005, J. Paula-Souza, M. S. Ferrucci, J. G. Rando & R. Tsuji 5485 (holotype ESA 91122 !; isotype BHO!) .

Herbs, 20–70 cm high, branched or simple, erect; stems tomentose to villous, less frequently pubescent, internodes 1–4 cm. Leaves alternate, the basalmost pair often opposite; petiole 0.5–1 cm; blade 3–8.6 cm long, 1–2.9 cm wide, elliptic or lanceolate, apex acuminate, margin serrate, base attenuate, puberule or subglabrous, usually pubescent along nerves. Flowers white, yellow, purplish or lilac, solitary, axillary; floral “pedicel” 6–7 mm, tomentose to villous or less frequently pubescent; bracteoles ca. 1–1.5 mm long, ca. 0.3 mm wide, linear; sepals slightly unequal, 3.5-5 mm long, ca. 1 mm wide, lanceolate, subfalcate, apex acuminate, margin entire, ciliate, base truncate, tomentose or less frequently pubescent; superior petals 3–4.5 mm long, 1–1.5 mm wide, oblong to elliptic or lanceolate, subfalcate, apex acute to obtuse, subciliate; lateral petals 3.5–6 mm long, 1.5–2.5 mm wide, ovate, lanceolate or less frequently oblong, falcate, apex obtuse or round, pubescent at apex; anterior petal 7.5–12.5 mm long, clawed, claw 3–5 mm long, blade (2-) 3.5–7 mm long, 2.5–7 mm wide, deltoid, triangular, suborbicular, widely to transversely elliptic or rhombic, apex obtuse or apiculate, base round, truncada or obtuse, pubescent to villous at the central part; filaments ca. 0.5 mm long, anthers ca. 1 mm long, connective appendages orange-brown, ca. 0.5–1 mm long, apex truncate, acute or round, asymmetric, the 2 anterior stamens each bearing a noduliform gland at the base of the anthers, villous; style 1.5–2 mm long, bearded, ovary ca. 0.5–1 mm long, glabrous. Capsule 5.5–7 mm long, 6–7 mm diam., globose or ovoid; seeds 2.5–3 mm long, 1.5–2.5 mm diam.

Distribution and habitat: — Pombalia barbata is endemic to caatingas from Ceará to Northern Minas Gerais states in Brazil, usually on shaded and humid places.

Etymology:—The epithet “ barbata ” refers to the bearded indument of the style ( Fig. 1 ), a strip of hairs covering the anterior part of this structure throughout its length, a very distinct feature of the new species.

Additional specimens examined (paratypes): — BRAZIL. Alagoas: Delmiro Gouveia, AL-220, 2km da cidade em direção à Fazenda Cachoeirinha, Caatinga, 22 Jul 1982, M.N.R. Staviski & R.P. Lyra 273 (MAC). Bahia: Bom Jesus da Lapa, ca. 11km S do entroncamento para Bom Jesus da Lapa na estrada para Malhada, Caatinga, 13º41’08”S, 43º28’06”W, 11 Feb 2000, L.P. Queiroz et al. 5896 (ESA, HUEFS). Caetité, Faz. Baixa Grande, caminho para Pajeú do Vento, Caatinga, 820msm, 14º04’03”S, 42º38’12”W, 09 Feb 1997, B. Stannard et al. PCD 5291 (ALCB, CEPEC, HRB, HUEFS, SPF). Iaçu, Fazenda Lapa, Estepe arbórea (caatinga), 12º42’S, 39º56’W, 26 Feb 1983, Arouck Ferreira 252 (ALCB, GUA, HRB). Iaçu, Faz. Suíbra, Morro do Gado Bravo, Caatinga e mata baixa, ocasional na beira da mata, 14 Mar 1985, L.R. Noblick 3702 (CEPEC, HUEFS). Iaçu, Fazenda Suíbra, ca. 10km de Iaçu pela estrada de terra seguindo a ferrovia, beira de córrego, elev. 245m, 12º44’16”S, 40º07’32”W, 05 Feb 2005, J. Paula-Souza et al, 5440 (ESA). Iaçu, saindo da BR 116, em direção a Lajedo Alto, Estepe Arbórea (caatinga), solo areno-argiloso, 12º46’S, 39º49’W, 26 Feb 1983, G.C.P. Pinto et al. 143/82 (HRB). Iaçu, estrada Iaçu—Milagres, Fazenda Santo Antônio, elev. 300m, Caatinga aberta utilizada como pasto, com afloramento rochoso e lagoa adjacentes, 12º48’S, 40º05’W, 20 Jul 2001, J.P. Souza et al. 3587 (ESA). Milagres, 11km antes do entroncamento para Iaçú, Caatinga, solo arenoso sobre afloramentos rochosos, perto de água, 10 Feb 1997, A.M. Giulietti. et al. PCD 5476 (ALCB). Palmeira, ca. 2,2km da entrada para Palmeiras a partir da BR 242, beira de estrada, caatinga, elev. 700m, 12º27’50”S, 41º35’02”W, 29 Jan 2005, J. Paula-Souza et al. 5029 (BHO, ESA). Mina Caraiba , 22 Mar 1966, A. Castellanos 25920 (HB). Mina Boqueira, Morro Sobrado , 02 Apr 1966, A. Castellanos 25997-a (HB). Ceará: Santa Quitéria, Fazenda Itataia, caatinga, 26 Apr 1984, A. Fernandes et al. s.n. (EAC 12459, ESA 62798). 1910, A. Loefgren 150 (R). Sobral, Fazenda Macapá (Taperuaba), 25 Apr 1977, A. Fernandes et al. s.n. (EAC 3187, ESA 62805). Sobral, Fazenda Macapá (Taperuaba), 29 Mar 1991, A. Fernandes et al. s.n. (EAC 17128, ESA 62797). Minas Gerais: Itaobim, rodovia para Jequitinhonha, entrando numa estrada de terra a 2,2km da BR 116, Caatinga, elev. 265m, 16º33’47”S, 41º29’18”W, 07 Feb 2005, J. Paula-Souza et al. 5554 (BHO, ESA). Pernambuco: Mirandiba, Fazenda Pau de Leite, 10 Mar 2008, A. Amorim et al. 251 (NY). Parnamirim, Km 33, estrada Parnamirim-Petrolina, Caatinga, 24 May 1984, F. Araújo 93 (ESA, IPA, UB). Parnamirim, Km 27, estrada Parnamirim-Petrolina, Fazenda Mulungu, Caatinga, 18 Jun 1984, F. Araújo 156 (MBM, UB). Paulista, 11 May 1983, M. Ataide s.n. (IPA 47819). Entre Serra Talhada e Petrolina, próximo à rodovia, 17 Apr 1971, E.P. Heringer et al. 4 (ESA, IPA, R, RB, UB). Sergipe: Canindé do São Francisco, Parque Ecológico Lagoa do Frio, 22 Jul 2005, K. Costa & A.G. Magalhães 512 (ESA). State? Cedro, 07 Jun 1933, P. Luetzelburg 26497 (M).

Discussion: —The Violaceae is a very well represented group in the Caatinga, either by endemic taxa or species that have this region as their core distribution. However, the only published account comprising all the species of Pombalia in this area dates back from 1871, in Eichler’s monograph of the family for Flora brasiliensis. Unpublished data ( Souza 2002) are being updated according to the recent changes in the suprageneric classification of the family and should be released soon. The discovery of several new taxa—including a new genus—from the Caatinga within a relatively short period ( Paula-Souza & Souza 2003a, 2003b, Paula-Souza et al. 2010) just reinforces the necessity of intensive taxonomic studies in this Bioma and this family.

The habitats in which the endemic Pombalia barbata are found correspond to what have been considered as refuges that minimize the effects of the dry season, thus enabling the survival of individuals ( Albuquerque et al. 2012). These microhabitats provided by the shades of nondeciduous tree species are known to influence the dynamics of the vegetation in semiarid conditions, but this subject is still poorly understood.

Pombalia barbata is morphologically close to Pombalia communis and Pombalia attenuata , from which the new species can be distinguished by the features provided on Table 1. Its herbaceous habit and noduliform glands at the anterior stamens are similar to those in P. attenuata , but other distinctive morphological characteristics, as well as the discrepant geographical distribution enable us to recognize it as a new species— P. attenuata is distributed from Southern United States to Colombia, Venezuela, Ecuador, Bolivia and Peru, and has not been recorded elsewhere in South America so far. Its recognition as a new species is further supported by preliminary molecular data ( Paula-Souza 2009), which indicate a very remote affinity between P. attenuata and P. barbata , and only a weak relatedness with P. communis .

IUCN Conservation assessment: —There is a single record of Pombalia barbata from a conservation unit in Sergipe state, the Ecological Park Lagoa do Frio; however, the species is frequently found in disturbed sites such as pastures and roadsides, where the holotype was found. The estimated area of occupancy (AOO) of Pombalia barbata is 60km 2, which preliminarily included it at the Endangered IUCN category (EN), based on B2 criteria (AOO less than 500km 2). Given the high number of known collection sites and its frequent occurrence in anthropic areas with no signs of declining populations, which was attested by direct field observations, the conservation status of Pombalia barbata is nevertheless considered Least Concern (LC).

Figures

FIGURE 1. Pombalia barbata. A. Habit; B. Sepal; C. Gynoecium, floral “pedicel” and bracteoles; D1-D6. Variations in corolla shape; E. Flower with perianth removed; F1. Posterior stamen; F2-F4. Morphological variation of the anterior stamens.

FIGURE 2. Geographical distribution of Pombalia barbata, and the area covered by the Caatinga in detail.