Lepidaploa scintillans Dematt. & D. Marq., 2016

Marques, Danilo & Dematteis, Massimiliano, 2016, A new species of Lepidaploa (Asteraceae: Vernonieae) from Minas Gerais State, Brazil, Phytotaxa 273 (2), pp. 133-138 : 134

Lepidaploa scintillans Dematt. & D. Marq. , sp. nov. ( Figs 1–4 )

Erect shrub, ca. 1.5 m tall. Leaves spirally alternate, subsessile; blade lanceolate, coriaceous to chartaceous, discolor due to indumentum, margin entire, apex acute to acuminate, basally attenuate, both surface sericeous, nacreous, argent. Capitulescence seriate-cymose, short, recurved. Florets 10–12 per capitulum, corolla lilac, tube glabrescent, lobes lanceolate, sericeous, glandular, apex acuminate. Pappus biseriate, outer series subpaleaceous, inner series bristles.

Type:— BRAZIL. Minas Gerais: Nova Porteirinha, Torre da CEMIG, 14 April 2007, J. M. Silva & O. S. Ribas 5655 (holotype: MBM!; isotype: CTES!) .

Description: —Erect shrub, ca. 1.5 m tall, branched. Branches ca. 0.2 cm in diam., terete, striated, densely sericeous, white to grayish, leafy up to capitulescence, internodes 0.5–1.2 cm long. Leaves spirally alternate, simple, discolor due to indumentum, petiolate, ca. 0.3 cm long, coriaceous-chartaceous; blade 5.5–6.4 × 0.1–0.3 cm, lanceolate, entire, apex acute to acuminate, base attenuate, both surfaces sericeous, nacreous, argent, pinnatinervate, veins prominent above, sericeous. Capitulescence 3.8–5.6 cm long, seriate-cymose, short, recurved, branches 4–6, short, with 6–7 capitula, leafy. Bracts of capitulescence leafy, 1–1.9 × 0.3–0.6 cm, lanceolate, sericeous. Involucre 6.4–7.7 mm long, homogamous, discoid, campanulate, peduncles 0.1–0.2 cm long; phyllaries 38–46 per capitulum, 6–8-seriate, sericeous, whitish; outer 2–3 × 0.5–0.8 mm, lanceolate to linear-lanceolate, apex apiculate, margin serrulate; inner 6.2–6.5 × 2– 2.1 mm, elliptic-lanceolate, apex apiculate, margin serrulate. Florets 10–12, androgynous; corolla actinomorphic, lilac, tube 3.3–3.7 mm long, cylindrical, glabrescent, lobes 4.3–4.6 mm long, lanceolate, pilose, trichomes glandular and eglandular, apex acute; anthers 3.6–4.3 mm long, apical anther appendages acute, basal anther appendages caudate; styles 10.2–11 mm long, with hairs below bifurcation point of style arms; stylopodium cylindrical, brown. Cypselae 1.8–2.4 cm long, obconic, angled, sericeous, glandular, with idioblasts and prismatic crystals on wall; carpopodium annular; pappus biseriate, cream-coloured, outer series 0.9–1.1 mm long, subpaleaceous, inner series 4.4–5.5 mm long, bristles. Pollen grains (type G): prolate-spheroidal (P/E: 1.14 μm), triporate, echinolophate, polar axis 23.12 (23.8) 25.84 μm; equatorial diameter 19.04 (20.74) 23.12 μm. Pore lolongate, 6.8–8.16 × 5.44–6.8 μm. Exine, excluding spines, 4.08 (4.76) 5.44 μm. Tectum descontinuous, irregular caveate, surface microperfurate, spines 2.04 (2.55) 62.72 μm long.

Distribuition and ecology:— The new species occurs in Nova Porteirinha, Minas Gerais, Brazil. The analyzed material has been found in the Cerrado.

Phenology:— Flowers and fruits of this species were collected from April. However, flowering time might be extended to March and/or May.

Etymology:— The specific epithet refers to shimmering leaves of the species.

Discussion:— Lepidaploa scintillans is readily recognized by the sericeous, nacreous and argent indumentum of both leaf surfaces, and subpaleaceous outer pappus. The new taxon is a distinctive species because of the features mentioned above, but it can be confused with L. persericea Robinson (1990: 292) because of the indumentum type of the leaves. Morphological comparisons between L. scintillans and L. persericea are summarised in Table 1.

Figures

FIGURE 1. Lepidaploa scintillans (isotype). A: Plant. B: Capitulum. C–K: Phyllaries series. L: Cypsela with pappus. M: Floret. N: Detail of corolla lobes. (A–N: from J.M. Silva & O.S. Ribas 5655, CTES; illustrated by Mirtha L. Gómez).

FIGURE 2. Lepidaploa scintillans details (holotype): A: Branch. B: Flowering branch showing the leaves. C: Capitula. (A–C: from J.M. Silva & O.S. Ribas 5655, MBM; imaged by Eduardo D. Lozano).

FIGURE 3. Floral microcharacters of Lepidaploa scintillans (LM): A: Corolla lobes with eglandular trichomes (black arrow). B: Corolla lobes with glandular trichomes (black arrow). C: Acute apical anther. D: Caudate basal anther. E: Basal style node (white arrow). F: Cypsela with idioblasts (black arrow).

FIGURE 4. Pollen of Lepidaploa scintillans (LM): A: Polar view, high focus. B: Polar view, middle focus. C: Equatorial view, mesocolpium, high focus. D: Equatorial view, high focus. Scale bars= 10 μm.