Delairea aparadensis Funez & Hassemer, 2021

Funez, Luís A., Hassemer, Gustavo, Peroni, Nivaldo & Drechsler- Santos, Elisandro R., 2021, Delairea aparadensis (Asteraceae, Senecioneae), the first native species of the genus in the Americas, Phytotaxa 494 (1), pp. 122-128 : 123-125

Delairea aparadensis Funez & Hassemer , sp. nov.

Type: — BRAZIL. SANTA CATARINA: Urubici, Parque Nacional de São Joaquim, Morro da Igreja , 1780 m, 13 March 2020, L. A . Funez & W. I. Ribeiro-Nardes 9796 (holotype: FLOR!; isotypes: FURB!, HTL!, HBR!) .

Diagnosis: —The new species differs from Delairea odorata by its leaves deltoid and capitulescences composed by cymes of 2–6 capitula vs. leaves subcordiform polygonal-lobed and capitulescence composed by dozens of capitula.

Description: —Perennial scandent subshrubs 40–150 cm tall. Stems green, erect, branching from the basal portion and often along its length, ca. 3 mm diam. on the basal portion gradually thinner toward the apical portions, striate, glabrous, apically foliose. Leaves gradually decreasing in size towards the apex, petiolate, petioles purple, 11–18 mm long, cylindric, glabrous, sulcate adaxially, blades deltoid, 18–62 × 15–65 mm, apex acuminate, base truncatesagittate, with two more prominent teeth and more 2–6 smaller teeth, venation actinodromous, secondary veins adaxially and abaxially raised, reticulate, coriaceous, glabrous on both surfaces, margins slightly revolute, (6)–8–10 teeth. Capitulescences terminal and axillary, 2–6 capitula disposed in a lax corymb 5–45 mm long, glabrous or with sparse arachnoid hairs on the axes. Capitula homogamous, discoid, pedunculate; peduncles 1–5 mm long, bracteolate, glabrous or with arachnoid hairs; bracteoles 1–2, rhombiform, 0.8–6 mm long, glabrous or very scarce arachnoid trichomes. Involucre cupuliform, 4–5 × 3–4 mm, calyculate; bracts of calycule ca. 5, lanceolate, 0.8–6 mm long; involucral bracts 7, lanceolate, 4.0–4.5 × 0.8–1.2 mm wide, apex acute, margin entire, glabrous with an apical tuft of hairs; receptacle plane and glabrous. Florets 15–22, perfect, corolla yellow, tubulose, tube 0.4–2.1 mm long, limb 1.5– 3.0 mm long., five triangular lobes up to 0.6 mm long; anthers 1.6–2 mm long, connectival appendage oblong, 0.7–0.8 mm long; style 3.0– 3.5 mm long, style branches with truncate apex, 1.0– 1.3 mm long. Ovary cylindrical, 1.0–1.2 × ca. 0.2 mm, costate, glabrous, carpopodium symmetrical, setose; pappus 4.0– 4.5 mm long, uniseriate, bristles numerous 60+, white, filiform, deciduous.

Photographs: — Figure 1 .

Etymology: —The specific epithet makes reference to the Aparados da Serra Geral, a region in southern Brazil where the new species is endemic to.

Phenology: —Flowering in March and fruiting probably from April to May.

Distribution and habitat: —The new species is endemic to Morro da Igreja, in Parque Nacional de São Joaquim, at Urubici, Santa Catarina state, southern Brazil ( Figure 2 ). It occurs in Cloud Forest environment, at elevations of 1700–1800 m.

Conservation status: —Critically Endangered—CR-B2a,b(iii). Delairea aparadensis has a confirmed area of occupancy (AoO) of less than 1 km 2, with only one population known. The species unfortunately cannot be considered satisfactorily safe, because of the ongoing trend of reduction of environment protection areas in the region, due to the pressure caused by the agricultural advance in Santa Catarina state ( Hassemer et al. 2015) and in Brazil as a whole, leading to the conversion of natural environments in agricultural and silvicultural lands. According to Hassemer et al. (2015), Asteraceae is the family with most species exclusive to Santa Catarina state. Some examples of micro-endemic especies of Asteraceae in the Aparados da Serra region are Baccharis chionolaenoides Falkenberg & Deble (2010: 64– 67) , Baccharis scopulorum Schneider & Heiden (2011: 9–13) , Conyza retirensis Cabrera (1959: 196) , Hysterionica matzenbacheri Schneider in Schneider & Boldrini (2012: 51–54), Hysterionica pinnatisecta Matzenbacher & Sobral (1996: 16) , Malmeanthus catharinensis King & Robinson (1980: 226–227) , besides these examples there are dozens of micro-endemic species from other families and an elevate number of rare and threatened species.

Observations: —This species is morphologically extremely distinct from all South American species of Senecioneae . According to the identification keys in Cabrera (1957), the new species matches best with Senecio sect. Delairea Bentham & Hooker (448: 1873) due the climbing habit, with foliose stems, leaves succulent, palmatinervate, capitulescences in dense cymes capitula discoid, homogamous, style branches truncate, pilose on the apex, and glabrous cypselae. According to the current classification of the tribe (e.g. Nordenstam 2007), Cabrera’s Senecio sect. Delairea is accepted as the hitherto monotypic genus Delairea , with its sole species, D. odorata (= S. mikanioides Otto ex Walpers [1845: 42] ), being a South African native that was introduced and became naturalised in many continents.

Despite these similarities, D. aparadensis is notably distinct from D. odorata , being a scandent subshrub vs. vines in D. odorata , the leaves are deltoid with dentate margins vs. subcordiform polygonal-lobed with entire margins in D. odorata . Additionally, the capitulescence of D. odorata is composed by dozens of capitula vs. 2–6 capitula in D. aparadensis . Despite the fact that D. odorata can be found cultivated, naturalised or invasive in the Americas, also in southern Brazil, this species is originally from South Africa, while D. aparadensis is, according to all evidence, native to the southern Brazilian cloud forests, an environment known for high prevalence of plant endemism ( Hassemer et al. 2015).

Figures

FIGURE 1. Delairea aparadensis. A. Capitulescence in frontal view, with four capitula, showing the homogamous flowers. B. Capitulescence in lateral view, showing the rhomboid bracteole, calycule and involucre. C. Apex of a flowering branch. D. Leaf blade in adaxial surface. E. Leaf blade in abaxial surface. F. Habit.

FIGURE 2. Distribution map of Delairea aparadensis (Asteraceae, Senecioneae) in Santa Catarina state, southern Brazil.