Lessingianthus paraguariensis Dematt., 2012

Angulo, M. B., 2012, New species of Lessingianthus (Asteraceae, Vernonieae) from Brazil and Paraguay, Blumea 57 (2), pp. 109-113 : 112-113

2. Lessingianthus paraguariensis Dematt. , sp. nov. — Fig. 2 , 3d –f

Lessingiantho asterifloro simile sed capitulis solitaris et phyllaris aequo longibus differt. Frutex erectus, caulibus gracilibus laxe foliatis. Inflorescentiae cymosa,ramis 2–3,erectis. Capitula sessilia,solitaria,hemisphaerica, 10–13 mm altae.— Typus: A. Schinini, M. Dematteis, R. Duré & M. Quintana 35897 (holo CTES; iso G, PY), Paraguay, Amambay, 27 km N de P. J. Caballero , S22°21'05", W55°55'24",en campos cerrados,suelo arenoso,quemados de la Sierra de Amambay, semi erecta, flores violáceas, follaje discolor, envés blanquecino, 6 Mar. 2002 .

Erect shrub, 50– 80 cm tall. Stems 2– 3, striate, laxly leafy, densely tomentose, whitish, 3.5 –4.5 mm diam. at the base, basal internodes 10–15 cm long, middle internodes 2– 3 cm long. Leaves alternate, sessile, coriaceous, discolour, the greatest 6 – 8 by 3 –4 cm, placed on the middle portion of the stem. Leaf blades broadly elliptic, entire, acute at the apex, obtuse at the base, glabrous or scarcely lanate above, white-tomentose beneath, pinnatinervate, secondary veins 10–15, scarcely curved. Bracts of the inflorescence absent. Inflorescence corymbiform, erect, with 2 –4 heads. Capitula pedunculate, peduncles 10–15 mm long, tomentose. Involucre hemispherical, 10–12 mm high, 15–17 mm diam. Phyllaries 2 –3 seriate, laxly imbricate, the outer ones linear to linear-lanceolate, acute, densely tomentose, 10–15 by 1–1.5 mm, inner phyllaries lanceolate, acute to acuminate, glabrous to apically tomentose, 8 –10 by 1.6– 2 mm. Florets purple to violet. Corollas glabrous, 13 –14 mm long, lobes lanceolate, 4 – 4.5 mm long, papilose at apex, with small glandular and eglandular hairs. Anthers basally caudate, 3.8– 4 mm long, apical appendage ovate, 0.4 –0.45 mm long. Style 14–15 mm long, branches linear, 3 – 3.5 mm long. Cypselas ribbed, laxly sericeous, densely covered of idioblast, raphides quadrangular to prismatic, 3.3– 3.5 mm long. Pappus white, biseriate, outer scales fimbriate, irregular, 1.2–2.1 mm long, inner bristles 9 –10 mm long. Pollen grains oblate-spheroidal (P/E = 0.98), 3-colporate, echinolophate. Colpi long, with apices visible in polar view. Polar diam. 47.6–(48.4)–48.9 μm, equato- rial axis 48.9–(49.3)–50.3 μm. Exine thickness 5.1–5.3 μm. Tectum discontinuous. Lacunae 10–12 µm diam., disposed in a regular pattern, polar lacuna absent. Tectum surface densely microperforate and spinose; spines 2.8 μm long, acute at apex.

Distribution — Paraguay (Amambay).

Habitat & Ecology — In campo and on grassy savannas with dry, rocky soils. Flowering and fruiting in January and March.

Etymology — The specific epithet refers to the region where the species occur.

Additional specimens examined. PARAGUAY, Amambay, in altoplanitie et declivibus Sierra de Amambay, Jan. 1907 /1908, T . Rojas 10060 ( BM, G) .

Note — Lessingianthus paraguariensis is closely related to L. asteriflorus (Mart. ex DC.) H.Rob. and L. mollissimus (D.Don) H.Rob. , but it can be distinguished by the broadly elliptical leaves and the size of the outer phyllaries, larger than the inner ones. Lessingianthus asteriflorus and L. mollissimus have lanceolate to oblong-lanceolate leaves and outer phyllaries shorter than the inner ones. In addition, the new species has the larger leaves in the middle portion of the stem, while L. asteriflorus and L. mollissimus have the larger leaves at the base of the stems.

Figures

Fig. 2 Lessingianthus paraguariensis Dematt. a. Plant; b. capitulum; c, d. outer phyllaries; e. middle phyllary; f, g. inner phyllaries; h. corolla showing anthers; i. corolla lobe (all: Schinini, Dematteis, Duré & Quintana 35897, CTES).

Fig. 3 Microcharacters and pollen grains of the new species. a–c. Lessingianthus cipoensis; a. corolla lobe apex; b. pollen grain, polar view; c. pollen grain, equatorial view; d–f. L. paraguariensis; d. idioblasts; e. crystals of the achene wall; f. corolla lobe apex (a–c: Hatschbach 30041, MBM; d–f: Schinini et al. 35897, CTES).