BRAZIL – Minas Gerais • Cristália, Jacuba, estrada Cristália-Botumirim, próximo ao córrego Jacuba; 700 m; 28 Sep. 1997; fl. and fr.; Mello-Silva 1449; holotype: SPF; isotypes RB, R, SP, BHCB.

Vellozia albohexandra is similar to V. armata by the tristichous leaves roughly of the same dimensions. However, V. albohexandra has sessile flowers (vs pedicel approx. 1.5 cm long in V. armata), white sepals and petals (vs violet in V. armata), 6 stamens (vs 18 stamens in V. armata), and capsule 5.7–6.7 × 5.3–6.2 mm (vs 10 × 6–9 mm in V. armata).

Stems 3.8–15 cm long. Leaves tristichous; leaf lamina 3.7–9.4 × 0.5–0.8 cm, linear-triangular, caudate, arcuate, involute, sparsely serrate on margins and midrib on abaxial side, abscission line absent, the old laminae marcescent and reflexed. Flowers solitary, sessile; hypanthium ca 0.5 × 0.2 cm, obtriangular, densely covered with subulate emergences, green. Perianth white; sepals 0.9–1.3 × ca 0.2 cm, oblanceolate, margin and midrib of apex and base sparsely covered with subulate emergences on abaxial side, adaxial smooth; petals 1.0–1.2 × 0.1–0.2 cm, narrowly-obovate, smooth or sparsely covered with subulate emergences on the base of abaxial side, adaxial smooth. Stamens 6, appendages absent; filaments separated, 2.5–4.0 mm long, colour not seen; anthers 3.6–4.5 mm long, basifixed, colour not seen. Style 9.1–10 mm long, white-yellowish; stigma 1.3–1.4 mm diam., trilobate-peltate, yellow. Capsule loculicidal, ellipsoid to broadly ellipsoid, 5.7–6.7 × 5.3–6.2 mm, ochre. Seeds not seen.

Blade dorsiventral (Fig. 2A). Abaxial furrows about one fifth thickness of blade (Fig. 2A). Cuticle slightly thickened on both surfaces (Fig. 2A). Adaxial epidermis 2–4-seriate (Fig. 2A–B), abaxial epidermis uniseriate (Fig. 2A). Stomata paracytic, confined to furrows (Fig. 2D). Cells elliptically clustered present on adaxial epidermis (Fig. 2C). Aquiferous uniseriate hypodermis present on adaxial surface, extending adaxially to the bundle sheaths as aquiferous parenchyma (Fig. 2A–B). Palisade mesophyll 3(–4) cell-layers thick (Fig. 2A–B). Fibro-vascular bundles surrounded by a unique bundle sheath, 1–3 large vessels present in each fibro-vascular bundle (Fig. 2A). Phloem strands 2, separated (Fig. 2A). Bundles of sclerified cells 2–7 cells thick present on the adaxial epidermis, spaced each 3–6 epidermal cells (Fig. 2A–B). Blade borders with large and rounded fibro-vascular bundles, conduction tissues present (Fig. 2A).

Vellozia albohexandra is endemic to the southern Espinhaço Range in Cristália municipality, Minas Gerais state, Brazil (Fig. 3). The species occurs in rock cracks of campo rupestre areas, at elevations around 700 m.

Collected with flowers and fruits in September.

The epithet refers to the flowers with white perianth and six stamens.

To date, Vellozia albohexandra is known only from the type locality and is therefore classified as Data Deficient (DD).

Vellozia albohexandra can be easily distinguished from the other species of the V. luteola group by its sessile flowers, with white and smaller petals and sepals, six stamens, and smaller style and stigma (Table 1). The combination of sessile white flowers with six stamens is rare among the species of Vellozia. Vellozia sessilis L.B.Sm. ex Mello-Silva has a white perianth and six stamens, but despite its specific epithet, this species has pedicels with ca 1 cm long that is hidden among the old persistent laminae (Mello-Silva 1997). Vellozia sessilis is distinguished from V. albohexandra mainly by its long hypanthium tube and general plant size and habit (Mello-Silva 1997).

BRAZIL – Minas Gerais • Itacambira, Serra de Itacambira. Estrada Juramento Itacambira, 46 km do balneário de Juramento, 250 m a oeste da estrada; 17°00’36.8”S, 43°20’28.5”W; 1280 m; 24 Dec. 2017; fl.; R. Mello-Silva 4347, A. Cabral, F.K. Kiataqui & D.Y.M. Nakamura; holotype: SPF; isotypes RB, R, SP, BHCB.

BRAZIL – Minas Gerais • Itacambira, Estrada para Montes Claros; 9 Jan. 1986; fr.; Mello-Silva CFCR 9093; R [R000163051, R000163051a], SPF • Itacambira, Serra de Itacambira, a 45 km de Juramento; 17°04’S, 43°20’W; 1200 m; 14 Feb. 1988; fr.; Pirani 2259; NY [NY00898964], SPF • Itacambira, no alto da serra; 17°04’S, 43°18’W; 1200 m; 14 Feb. 1988; fr.; Pirani 2275; NY [NY00898963], SPF.

Vellozia mellosilvae resembles V. armata by their tristichous phyllotaxis, violet perianth, and overlapping number of stamens, and dimensions of anther, style, and stigma. However, V. mellosilvae differs by the longer (1.6–4.2 cm vs 1.5 cm in V. armata) and evident pedicel (vs completely hidden by the leaves in V. armata), larger petals and sepals (2.5–4.2 × 0.9–1.2 cm vs 1.5–2.3 × 0.5 cm in V. armata), leaf furrows (present vs absent/reduced in V. armata), and margin (serrate vs spinescent in V. armata).

Caespitose herb. Stems 2.1–11.2 cm long. Leaves tristichous; leaf lamina 11.9–29 × 0.6–1.3 cm, linear-triangular, caudate, arcuate, involute at the base, sparsely serrate on margins and midrib of the abaxial side, abscission line absent, the old laminae marcescent and reflexed. Flowers 1–4; pedicel 1.6–4.3 cm long, sparsely covered with subulate emergences, light green to yellowish-green; hypanthium 5–6 × 3–4 mm, obovoid, densely covered with subulate emergences, light green to yellowish-green. Perianth violet on the adaxial side and light violet on the abaxial side; sepals 2.8–3.7 × 0.9–1.3 cm, widely-oblanceolate, abaxial face and margin sparsely covered with subulate emergences, adaxial smooth; petals 2.5–4.2 × 1–1.2 cm, obovate, midrib of the abaxial side sparsely covered with subulate emergences on apical and proximal region, adaxial smooth. Stamens 18–20, 3–5 grouped, appendages absent; filaments irregularly united at the bottom, light-violet; anthers 6–11 mm long, basifixed, yellow. Style 14.6–23 mm long, white; stigma 2.4–4 mm diam., trilobate-peltate, yellow. Capsule loculicidal, ellipsoid to broadly ellipsoid, 8–18 × 6–10 mm, ochre. Seeds not seen.

Blade dorsiventral (Fig. 2E). Abaxial furrows about one fifth thickness of blade (Fig. 2E). Cuticle slightly thickened on both surfaces (Fig. 2E). Adaxial epidermis 2–3-seriate, abaxial epidermis uniseriate (Fig. 2E). Stomata paracytic, confined to furrows (Fig. 2G). Cells elliptically clustered present on both surfaces (Fig. 2F–G). Aquiferous 1(–2)-seriate hypodermis present on adaxial surface, extending adaxially to the bundle sheaths as aquiferous parenchyma (Fig. 2E). Palisade mesophyll 2–3 cell-layers thick (Fig. 2E). Fibro-vascular bundles surrounded by a unique bundle sheath, 1–3(–4) large vessels present in each fibro-vascular bundle (Fig. 2E). Phloem strands 2, V-shaped (Fig. 2E). Bundles of sclerified cells 2–8 cells thick present on the adaxial epidermis, spaced each 1–7 epidermal cells (Fig. 2E). Blade borders with large and rounded fibro-vascular bundles, conduction tissues present. Pedicel rounded in transverse section, fibro-vascular bundles 13, belt of sclerified cells absent (Fig. 2H–I).

Vellozia mellosilvae occurs in the campo rupestre of Itacambira municipality, southern Espinhaço Range, Minas Gerais state, Brazil (Fig. 3). This species is found in rocky outcrops among shrubs in sandy soil and rock crevices at elevations from 1,200 to 1,280 m.

Flowering in December and fruiting from January to February.

The epithet is named after Renato Mello-Silva (1961–2020), the greatest authority in the systematics of Brazilian Velloziaceae and who also collected the holotype of Vellozia mellosilvae.

Vellozia mellosilvae is endemic to the municipality of Itacambira and has an area of occupancy of 12 km² and extent of occurrence of approximately 11 km². Although it occurs in large populations, V. mellosilvae is not protected by conservation units. Besides that, the campo rupestre is a sensitive ecosystem to threats such as mining and livestock farming (Ribeiro and Freitas 2010). Therefore, V. mellosilvae is considered Critically Endangered: CR B1abiii.

Vellozia mellosilvae morphotype was already described under Vellozia luteola in Mello-Silva and Menezes (1988) based on vegetative characters and fruit morphology. However, the author observed conspicuous differences in the leaf anatomy between populations from the type-location of V. luteola and from Itacambira (i.e. presence/absence of bulliform cells and abaxial furrows). After analysing a recent collection of a flowering individual, we recognized the population of Itacambira as a distinct species. In addition to the characters highlighted by Mello-Silva (1988), V. mellosilvae can be differentiated from V. luteola by the violet perianth (vs yellow in V. luteola), sepal and petal dimensions (2.5–4.2 cm × 9–12.7 mm vs 1.5–2.5 cm × 4–7 mm in V. luteola) and presence and distribution of emergences on their abaxial surface, 18–20 stamens (vs 15 in V. luteola), anthers length (6–11 mm vs 4–7 mm in V. luteola), and stigma diameter (2.4–4 mm vs ca 6 mm in V. luteola) (Table 1).