Calea aldamoides G. Silva, Bringel & A. Teles, 2016

Silva, Gustavo Henrique Lima Da, Jr, João Bernardo De Azevedo Bringel & Teles, Aristônio Magalhães, 2016, A new species of Calea (Asteraceae-Neurolaeneae) from Goiás State, Brazil, Phytotaxa 265 (3), pp. 279-284 : 280

Calea aldamoides G. Silva, Bringel & A. Teles , sp. nov. ( Figs. 1–2 )

The new species is closely related to Calea multiplinervia and C. abbreviata , from which it differs by its leaves petiolate (vs. sessile), venation suprabasal acrodromous (vs. basal acrodromous), leaf blade widely lanceolate (vs. linear to oblong), and also from C. multiplinervia by its leaf margins entire to denticulate (vs. serrate to crenate); cypselae glabrous (vs. pubescent), and pappus scales (ca. 2 mm long) short than cypselae (3.9–4.2 mm long) [vs. pappus scales (5–7.5 mm long) longer than cypselae (3.5–5 mm long)].

Type:— BRAZIL. Goiás: Cavalcante, estrada para a Estação Ecológica Córrego Branco, 13°34’29”S, 47°43’46”W, 918 m, 01 February 2015, J. Bringel 1188 (holotype CEN!, isotypes MO!, RB!, UB!, UFG!).

Subshrub xylopodial, caespitose. Stems 55–82 cm tall, terete, hirsute. Leaves opposite, petiole 4–9 mm long, blade lanceolate, 5.2–11.5 × 1–2.8 cm, apex acute, base obtuse to acute, margins sparsely minutely serrate, revolute, sparsely hirsute on both sides, trichomes eglandular, venation suprabasal acrodromous. Capitula solitary, terminal,heterogamous, radiate; peduncle 25–36 cm long, sparsely hirsute; involucre campanulate, 12–15 × 12–15 mm; phyllaries 4-seriate, dimorphic, outer foliose, 6, lanceolate, 8–20 × 5–6 mm, apex acute, margins sparsely serrate, scabrous, inner scarious, 16–18, oblong to narrow oblong; outermost series 7–11 × 5.8–6.7 mm, intermediate series 10–13.5× 4.4–6 mm, innermost series 9.5–13 × 3–4.7 mm, apex obtuse; receptacle convex, paleaceous, paleae concave, linear, 6.5–8.5 × 0.8–1 mm, apex acute. Ray florets 11–15, corolla yellow, liguliform, tube ca. 3.8 mm long, limb oblong, 13–13.5 × 4–5 mm, apex 4-dentate; style ca. 5 mm long, branches ca. 1.7 mm long. Disk florets 45–67, bisexual, corolla yellow, tubular, 6.3–7 mm long, tube ca. 2 mm long, throat ca. 3 mm long, lobes 1.3–2 mm long; anthers ca. 3 mm long; style ca. 6.4 mm long, branches ca. 1.8 mm long. Cypselae 4-angled, 3.9–4.2 mm long, setulae only on angles; pappus scales lanceolate, ca. 2 mm long.

Distribution and ecology: — Calea aldamoides is currently known from the municipality of Cavalcante, near the Reserva Natural Serra do Tombador, in northern Goiás State ( Fig. 3 ). The species was found growing in an open cerrado vegetation (cerrado ralo), on cambisol soil, on slopes.

Conservation status: —The new species, following the IUCN Red list guidelines ( IUCN 2016), is considered Endangered (EN; subcriterion D—population size estimated to number fewer than 250 mature individuals) as it grows in a highly specialized habitat and is known from a single population. Although there is not enough environmental information, it is possible to infer that, in addition to the reduced population size, another threat to the new species is the increasing expansion of the agricultural frontier in Goiás State and the consequent loss and degradation of habitats in the Cerrado biome. Despite the new species was collected near the private reserve of Serra do Tombador (ca. 10 km NE), it has not yet been found inside the reserve.

Phenology: —Flowering and fruiting specimens were collected during the middle of Cerrado’s rainy season, in February, and certainly flowering and fruiting plants also may be collected in January.

Etymology: —The specific epithet of this new species is an allusion to its similarity with some species of Aldama La Llave ( Asteraceae , Heliantheae).

Discussion: — Calea aldamoides is closely related to C. multiplinervia Lessing (1830: 159) from which it differs by the leaf venation suprabasal acrodromous (vs. basal acrodromous), the pappus shorter than the cypselae (vs. longer than the cypselae), outer phyllaries foliose and scabrose (vs. scarious and glabrous). This new species is also similar to C. abbreviata in its growth habit and its pappus shorter than the cypselae, but differs in the petiole length (4–9 mm) and leaf blades that are lanceolate and pubescent (vs. leaves sessile, linear and glabrous). According to Pruski (1998), the species of Calea sect. Monanthocalea are recognized by the subshrubby and unbranched growth form, solitary capitula, pappus scales longer than the cypselae (mostly reaching the apices of the corolla lobes in the disk florets). Despite having pappus scales shorter than the cypselae, C. abbreviata was placed by Pruski (1998) in C. sect. Monanthocalea because of possessing other characteristics of the group, such as the monocephalous or few-headed capitulescence, the radiate and long pedunculated capitula, the subshrubby habit with xylopodia, and the linear paleae of the receptacle. In this way, C. abbreviata , C. rupicola , and C. aldamoides stand out for being the only species of the section in the Brazilian’s Central-West region with the pappus scales shorter than the cypselae.

Figures

FIGURE 1. Calea aldamoides. A. Habit. B. Leaf. C. Ray floret. D. Palea. E. Disk floret. (All illustrations made from the holotype. Drawings by the first author.).

FIGURE 2. Calea aldamoides, in vivo. A. Capitula showing the dimorphic phyllaries. B. Capitula showing the ray and disk florets. C. Habit. (Photos by J. Moises Mendoza F.).

FIGURE 3. Distribution of Calea aldamoides.