Pombalia cristalina Paula-Souza, 2021

Paula-Souza, J., Lima, A. G. & Souza, V. C., 2021, THE VIOLETS OF THE BRAZILIAN SAVANNA: A REVISION OF THE POMBALIA LANATA COMPLEX (VIOLACEAE), WITH DESCRIPTIONS OF TWO NEW SPECIES, Edinburgh Journal of Botany 78 (357), pp. 1-32 : 8-11

1. Pombalia cristalina Paula-Souza , sp. nov.

Pombalia cristalina is morphologically similar to P. strigoides (Taub.) Paula-Souza but is distinguished by its larger leaves 10–14 × 3–4.4 mm (versus 4–7.9 × 1.5–3 mm), smaller, c. 0.3 mm long connective appendages (versus 1–1.2 mm long) and white or creamy petals (versus purple, blue or lilac, rarely white).

– Type: Brazil, Goiás, Cristalina, estrada para Unaí , c. 600 m da BR 040, cerrado degradado com campo rupestre adjacente, 16.7453°S, 47.6047°W [16°44′43.1′′S, 47°36′16.9′′W], 1230 m a.s.l., 18 x 2006, J. Paula-Souza, G.O. Rom ã o & G.S. Leite 8611/6768 (holotype SPF [ SPF182079 ], isotype ESA [ ESA97122 ]). Figures 2A–D , 10F .

Suffrutescent herb, 10–15 cm high, branched from a well-developed, bud-bearing underground root-like system, erect; stems densely strigose, internodes 4–14 mm. Stipule 2–3 × c. 0.5 mm, narrowly elliptic, margin entire, hyaline and inconspicuous among the dense indument; leaves alternate, sessile; blade 10–14 × 3–4.4 mm, narrowly oblong, narrowly elliptic or narrowly lanceolate, apex acuminate, margin entire, base truncate, 1-nerved, densely strigose along the nerve especially at the base. Flowers white or creamy, with a yellow spot at the base of the anterior petal, solitary, axillary; pedicel 1–1.7 cm long, strigose; bracteoles 2–2.5 × c. 0.25 mm, linear; sepals slightly unequal, 3.5–5.8 × 1–1.3 mm, lanceolate, subfalcate, apex acuminate, margin entire, base truncate, densely strigose; posterior petals 5–5.8 × 1.7–2.1 mm, oblong to lanceolate, subfalcate, apex round; lateral petals 8.2–13.1 × 4.2–7.5 mm, falcate, clawed, the blade obtriangular, apex truncate or emarginate, villous beneath; anterior petal 13–15 × 6.7–18 mm, including a claw 5.5–6.5 mm long, transversely oblong, apex emarginate or less frequently truncate, base truncate or less frequently obtuse, villous; filaments 0.8–1.5 mm long, anthers 1.15–1.35 mm long, connective appendages hyaline, c. 0.3 mm long, apex round or apiculate, asymmetrical, the 2 anterior stamens each bearing a noduliform gland at the base of the anthers or in the middle of the filament, sometimes the gland inconspicuous corresponding to a swollen area, villous; style 3–3.5 mm long, glabrous, ovary 1.15–1.3 mm long, strigose, ovules 12(13). Capsule 7.5–8.5 × c. 7 mm, ovoid or ellipsoid; seeds not seen.

Etymology. The epithet refers to the municipality of Cristalina, where the new species is found. In addition to being well known for the production of gemstones and crystals, Cristalina is also recognised here for inhabiting ‘precious’ plants.

Distribution and habitat. Pombalia cristalina is known only from open savannas and campos rupestres around the municipality of Cristalina, Goiás state, central Brazil ( Figure 3 ).

Phenology. The species has been collected with flowers and fruits in September and October, with a single flowering record for July.

Conservation status. The municipality of Cristalina is situated at the junction of Brazil’s two major highways, which link the largest cities of the country to its capital city, Brasília. This has contributed to much of the growth and urbanisation of the area at the expense of its natural ecosystems. This region is one of the most important centres of production of crystals and gemstones in Brazil (hence the name), and potential environmental effects of this industry are an intense threat to its natural habitats. Personal observations have further indicated that agriculture is a relevant threat; at least two known populations have been drastically reduced and are struggling in cultivated fields of heavily mechanised crops. There is a single occurrence of this species from a small conservation unit. Therefore, according to IUCN (2012) criteria B1a,b(i,iii), Pombalia cristalina is considered Critically Endangered (CR) based on its very limited distribution (EOO, 13,413 km 2) and the continuing decline in the quality of its habitat.

Additional specimens examined. BRAZIL. Goiás: Cristalina, estrada para Unaí , c. 600 m da BR 040 , 16°44′43′′S, 47°36′17′′W, 1230 m a.s.l., 21 i 2005, Paula-Souza et al. 4326 ( ESA) ; c. 5 km da cidade em direção a Brasília , margem da BR-040, 29 vii 2007, M.A.Silva 6154 ( ESA, IBGE) ; BR-251 c. 1 km da cidade em direção a Brasília, 8 ix 2002, M.A.Silva & M.J.O.Souza 5363 ( ESA, IBGE) ; 4 km de Cristalina em direção a Unaí (GO-309), Serra dos Cristais, 10 ix 1998, Paula-Souza et al. 2746 ( ESA, SPF) ; estrada para a Pedra Chapéu do Sol , c. 400 m E da BR 040 , 16°44′48.2′′S, 47°36′26.2′′W, 1235 m a.s.l., 21 x 2012, Paula-Souza et al. 11237/611 ( ESA) .

The habit of this new species resembles that of Pombalia strigoides , but it has slightly larger leaves. In respect to floral features, a striking difference between the two species is in the connective scales of the anthers (see Figure 10E, F ), which are much larger in Pombalia strigoides . Additional differences are listed in the Table.

Figures

Figure 2. A–D, Pombalia cristalina Paula-SouZa, sp. nov.: A and B, flowering branches; C, habit; D, detail of vegetative branch. E and F, Pombalia insignis Paula-SouZa, sp. nov.: E, flower; F, habit and type locality. Photographs: A and B, Henrique Moreira; C and D, Juliana de Paula-Souza; E, Marco Batalha; F, Gérson de Oliveira Romão.

Figure 3. Distribution of Pombalia cristalina, P. insignis, P. poaya, P. strigoides and P. velutina.

Figure 10. A–E, Pombalia strigoides: A, habit; B, gynoecium; C, variation of size and shape of the corolla; D, calyx; E1, posterior stamen; E2–E4, variation of size, indument and shape of connective appendage of anterior stamens. F, Pombalia cristalina Paula-Souza, sp. nov.: anterior stamen. Drawn from Gifford & Fonseca 243 (A), Irwin et al. 9355 (B and E3), Rizzo 8407 (C1, D, E1 and E2), Heringer 2503 (C2 and E4) and Proença & Oliveira 1562 (F) by Rogério Lupo.