Paepalanthus multistellaris Andrino & Sano 2016, sp. nov.
Creators: name: Andrino, Caroline Oliveira
name: Trovó, Marcelo
name: Sano, Paulo Takeo
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Liliopsida
Poales
Eriocaulaceae
Paepalanthus
Paepalanthus multistellaris

description: Paepalanthus multistellaris Andrino & Sano, sp. nov. Figs. 1–3.
Type: — BRAZIL. Minas Gerais: Botumirim, “ Vereda/Várzea da Estiva ”, 7 March 2013, C.O. Andrino, P.T. Sano, P.M. Gonella & P.C. Baleeiro 236 (holotype SPF, isotypes DIAM, RB, P, NY, B).
Paepalanthus multistellaris is most similar to Paepalanthus hirtellus because of its long, ascending stem and scapes arranged in a terminal umbel, but immediately distinguished by its leaves glabrescent on the abaxial surface, spathes glabrous, and mainly by the green involucral bracts linear to lanceolate surpassing the flowers in length.
Perennial herbs, 26–110 cm long. Stem elongated, 16.0–95.0 cm long, erect to ascending, covered by persistent and senescent leaves. Leaves spirally arranged along the stem, 3.0–9.0 × 0.2–0.6 cm, reflexed with age, linear to lanceolate, chartaceous, green, glabrescent on both surfaces, margin glabrous, apex acute. Sheaths tightly adpressed to scapes, 2.0–3.0 cm long, glabrous, margin ciliate, apex acute. Scapes 50–160 per fasciculate, umbel-shaped inflorescence, green, 6.0– 11.5 cm long, multicostate, pilose, trichomes ca. 1 mm long. Capitula hemispherical, white, 4.5–7.2 mm diam. Involucral bracts in 3 to 4 series, internal layers castaneous, lanceolate, 2.8–5.8 × 0.4–1.5 mm, external layers green, linear to lanceolate, 3.2–6.9 × 0.4–1.2 mm, surpassing the flowers, all of them glabrescent on adaxial surface, pubescent in the central apical area, margin ciliate. Flowers 3–merous. Floral bracts lanceolate-elliptic, ca. 3.0 × 0.5 mm, glabrous on both surfaces, ciliate from the middle toward the obtuse apex, cream-colored to golden, membranaceous. Pistillate flowers 3.5–6.0 mm long, pedicel 0.3–0.4 mm long; sepals obovate to lanceolate, ca. 3.0 mm long, cream-colored, glabrous on both surfaces, ciliate from the middle towards the obtuse apex; petals membranaceous, spatulate, ca. 2.0 mm long, cream-colored, hyaline, glabrous on both surfaces, ciliate towards the acute apex; gynoecium ca. 2.0 mm long, stigmatic branches bifid at the apex, 2× longer than the nectariferous branches; staminodes 3, scale– like. Fruits and seeds not seen. Staminate flowers 4.0–5.0 mm long; pedicel 0.8–1.0 mm long, with long trichomes; sepals free, lanceolate to obovate, 1.7 × 0.2 mm, glabrous on both surfaces, ciliate toward the acuminate apex; corolla tubular, membranaceous, cream-colored, hyaline, 3-lobed, glabrous; stamens 2.0– 2.7 mm long, anthers cream-colored; pistillodes 3, papillose.
Etymology: —The epithet multistellaris, meaning “many stars”, refers to the star-shaped capitula combined into a multiple-inflorescence, resembling a constellation.
Distribution, Habitat & Conservation: — Paepalanthus multistellaris is known from a single population, with about 50 individuals, in the municipality of Botumirim, Minas Gerais, SE Brazil (Fig. 3). It grows on seasonally wet sandy soils in a peculiar area where two distinctive vegetation types meet, the campos rupestres and the veredas —a seasonally flooded area with the presence of the palm Mauritia flexuosa Linnaeus (1782: 454; Fig. 2). Its distribution is restricted to a very small and unprotected area not larger than 1 km 2 that is prone to disturbance by human activities, such as fire and cattle grazing, and highly vulnerable to invasion of exotic grasses, such as Melinis minutiflora Palisot de Beauvois (1812: 54) and Brachiaria (Trinius 1826: 39) Grisebach (1853: 469). It is therefore categorized as Critically Endangered (CR), according to criteria B1ab + B2a of the IUCN Red List (2012).
Additional specimen examined (paratype): — BRAZIL. Minas Gerais: Botumirim, Várzea da Estiva, 01 December 2015, Costa et al. 1727 (DIAM).
Notes: — Paepalanthus multistellaris is placed in P. subsect. Actinocephaloides due to its trimerous flowers, an elongated and unbranched stem, and the fasciculate, umbel-shaped inflorescence usually inserted at the distal part of the stem. Paepalanthus multistellaris is a robust species, easily distinguished from all other species of Paepalanthus by its scapes arranged in an apical inflorescence and its green, lanceolate, outermost involucral bracts surpassing the flowers in length, an unusual character in the genus.
Paepalanthus bifidus (Schrader in Schultes1824: 468) Kunth (1841: 512) and P. uncinatus Gardner in Hooker (1843: 523) also have green involucral bracts surpassing the flowers. These two species are, however, quite distinct from P. multistellaris, and are placed into different infrageneric groups within the genus. Paepalanthus bifidus belongs to P. subsect. Paepalanthus (= Paepalanthus [unranked] Eupaepalanthus Ruhland 1903: 123) ser. Leptocephali Ruhland (1903: 152), and is an annual herb of very gracile habit, of only about 10 cm in height. Paepalanthus uncinatus is placed within P. subg. Xeractis Koernicke (1863: 308), and can be distinguished by the fewer (up to 11 per cohort) and longer (10–30 cm long) scapes, emerging from the leaf axil. In addition, P. uncinatus has the staminate flower corolla internally hairy, an exclusive characteristic of the subgenus to which it belongs.
Paepalanthus hirtellus Trovó et al. (2011: 26), also known from a single population in the municipality of Santo Antonio do Itambé, Minas Gerais state, is the species most similar morphologically to P. multistellaris. Both are robust herbs with erect to ascending, unbranched stems and fasciculate scapes. The sizes of leaves and scapes are also very similar in these species. Besides the green involucral bracts surpassing the flowers in length, P. multistellaris can be distinguished from P. hirtellus by its leaves glabrescent on the abaxial surface (vs. hirtellous), spathes glabrous (vs. hirtellous), and involucral bracts linear to lanceolate (vs. ovate).
description: Published as part of Andrino, Caroline Oliveira, Trovó, Marcelo & Sano, Paulo Takeo, 2016, A field full of green stars: Paepalanthus multistellaris (Eriocaulaceae), a new species from Minas Gerais, Brazil, pp. 55-61 in Phytotaxa 278 (1) on pages 56-60, DOI: 10.11646/phytotaxa.278.1.6, http://zenodo.org/record/13650671