Vellozia albohexandra Mello-Silva ex Andr.Cabral & Magri, 2022
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publication ID |
https://dx.doi.org/10.5091/plecevo.94326 |
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persistent identifier |
https://treatment.plazi.org/id/A94A322A-D951-58D3-8ACF-049BC799D991 |
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treatment provided by |
by Pensoft |
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scientific name |
Vellozia albohexandra Mello-Silva ex Andr.Cabral & Magri |
| status |
sp. nov. |
Vellozia albohexandra Mello-Silva ex Andr.Cabral & Magri sp. nov.
Figs 1 View Figure 1 , 2A-D View Figure 2 , 3 View Figure 3
Type.
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 .
Diagnosis.
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 ).
Description.
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.
Leaf and pedicel anatomy.
Blade dorsiventral (Fig. 2A View Figure 2 ). Abaxial furrows about one fifth thickness of blade (Fig. 2A View Figure 2 ). Cuticle slightly thickened on both surfaces (Fig. 2A View Figure 2 ). Adaxial epidermis 2-4-seriate (Fig. 2A-B View Figure 2 ), abaxial epidermis uniseriate (Fig. 2A View Figure 2 ). Stomata paracytic, confined to furrows (Fig. 2D View Figure 2 ). Cells elliptically clustered present on adaxial epidermis (Fig. 2C View Figure 2 ). Aquiferous uniseriate hypodermis present on adaxial surface, extending adaxially to the bundle sheaths as aquiferous parenchyma (Fig. 2A-B View Figure 2 ). Palisade mesophyll 3(-4) cell-layers thick (Fig. 2A-B View Figure 2 ). Fibro-vascular bundles surrounded by a unique bundle sheath, 1-3 large vessels present in each fibro-vascular bundle (Fig. 2A View Figure 2 ). Phloem strands 2, separated (Fig. 2A View Figure 2 ). Bundles of sclerified cells 2-7 cells thick present on the adaxial epidermis, spaced each 3-6 epidermal cells (Fig. 2A-B View Figure 2 ). Blade borders with large and rounded fibro-vascular bundles, conduction tissues present (Fig. 2A View Figure 2 ).
Distribution and habitat.
Vellozia albohexandra is endemic to the southern Espinhaço Range in Cristália municipality, Minas Gerais state, Brazil (Fig. 3 View Figure 3 ). The species occurs in rock cracks of campo rupestre areas, at elevations around 700 m.
Phenology.
Collected with flowers and fruits in September.
Etymology.
The epithet refers to the flowers with white perianth and six stamens.
Preliminary IUCN conservation assessment.
To date, Vellozia albohexandra is known only from the type locality and is therefore classified as Data Deficient (DD).
Notes.
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 View 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).
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