Valeriana iganciana Rabuske & Külkamp, 2018

Silva, Cassio Rabuske Da & Külkamp, Josimar, 2018, Valeriana iganciana (Valerianaceae), a new species from the highland grasslands of Serra do Tabuleiro, Santa Catarina, Brazil, Phytotaxa 364 (3), pp. 275-282 : 276-280

Valeriana iganciana Rabuske & Külkamp sp.nov. ( Figures 1 , 2 and 3 )

Type: — BRAZIL. Santa Catarina: São Bonifácio, Parque Estadual da Serra do Tabuleiro , trilha para o Morro das Pedras , 27°49’12.6”S 48°53’57”W, 1130 m elev., 19 August 2017, stam. fl., C.Rabuske, C.C.Alff & L.Nicoleite 279 (holotype ICN!, isotypes FLOR!, RB!) .

The new species is morphologically similar to Valeriana ulei Graebner (1899: 436) but differs in the leaves with at most 4 pairs of inconspicuous teeth in the apical third, with apex reflex forming pungent projection, perceptible to the touch (vs. 5–7 (10) pairs of conspicuous teeth 2–4 mm long, with apex not reflex), the fruits with 4 mm long, endowed with an annular or dentate calyx (vs. never exceed 2 mm long and the calyx is absent or vestigial), the architecture of the inflorescence is an compound cyme of only two secondary branches starting from the most basal bracts, never forming a main axis (vs. paniculiform inflorescences with 3–4 secondary branches from a main axis), growing on granitic soils of the Serra do Mar mountain range (vs. growing on basaltic soils of the Serra Geral plateau).

Dioic sub-shrub, 35–70 cm high, perennial, rhizomatous in young phenophases, branched in the median portion (26–30 cm high) in late phenophases; non-fistulous branches, internodes (4) 7–12 (18) mm long at base and (7) 14–26 (50) mm long at floral axis, 3–12 mm in diameter; plants glabrous except for the presence of tufts of hyaline trichomes 0.4–1.2 mm long, denser and conspicuous in the nodes of the floral branches and eventually presence of hyaline and sparse hairs, apressed and ascending, in the margin and central nerve of the abaxial face of the leaves, 0.1–0.8 mm long. Leaves opposite and decussate, persistent in the branches of the inflorescence, marcescent and deciduous in late phenophases, simple, elliptic, lanceolate, obovate, or more often oblanceolate, (25) 30–47 (54) × 9–20 mm, becoming smaller along the axis of the inflorescence, coriaceous, discolored and wrinkled when dried, adaxial surface finely bullate; apex rounded, obtuse, acute or acuminate; base cuneate, attenuated or obtuse, eventually sessile, with decurrent petioles of 11–24 mm long; central nerve adaxially sulcate, abaxially salient; secondary veins inconspicuous, the first pair stronger than others, diverging at a narrower angle than the other veins (about 30º); entire margin, markedly revolute, sometimes hyaline, with 1–3 (4) pairs of inconspicuous teeth restricted to the apical third of the leaf blade, associated with clear spots near the margin; teeth ca. 0.2–0.7 mm long; apex of the leaf blade acuminate, partially conduplicated, patent, perceived to the touch. Inflorescence terminal in compound cyme, with two secondary branches (paracladia, sensu Larsen 1986), with the final units dichasial, (12) 18–45 mm long. Bracts on the lower two nodes of the inflorescence (5) 7–10 (15) × 2–5 mm, lanceolate to oblanceolate, decurrent base, similar to upper leaves. Bracteoles lanceolate, 3 × 1 mm, green, sometimes with the vinaceous apical third, with hairs of about 0.1 mm long at the base. Flowers of both sexes sessile, pentamerous, the calyx inconspicuous with 4–5 completely fusionated segments forming a wavy ring, in some flowers forming hardly visible teeth, 0.1–0.2 mm wide. Staminate flowers white to cream, campanulate, 2–2.4 × 2 mm, with a small gibbosity of 0.2–0.5 mm long, corolla tube 0.9–1.2 × 0.9 mm, the lobes acute, 0.9–1.2 × 0.7–1.2 mm; stamens 3, 1.3–1.6 mm long, exserted, adnate to the corolla in the basal third; the anthers ovate to globose, 0.4–0.6 × 0.3–0.4 mm, bithecal; pistilodium 1.3–1.6 mm long, included. Pistillate flowers white, campanulate, 1–1.5 × 0.8–1.2 mm, corolla tube 0.5–0.8 mm long, lobes 0.3–0.6 × 0.4–0.5 mm, apex obtuse; vestigial staminodes 3, up to 0.2 mm long, epipetalous, laminar and apically rounded; style 1.3–1.8 mm long, exserted; trifid stigma, papillose, 0.2–0.3 mm long, with rounded lobes; ovary 1 mm long, unilocular, uniovulate. Fruits elliptical, 4 × 1.4–2 mm, apex rounded to obtuse, transversely triquetrous, 5–6-costate (with one abaxial, two lateral, and three adaxial vascular bundles), two prominent lateral winged projections, 0.5–0.7 mm wide, glabrous, densely papillose, uniseminate. Seeds examined immature.

Distribution and habitat: — Valeriana iganciana is known so far only for the highland grasslands on granitic soils of the Serra do Tabuleiro State Park, municipality of São Bonifácio, state of Santa Catarina, between 1100 and 1200 m elevation ( Fig. 3 ).

Conservation status: —the species is Critically Endangered (CR) according to IUCN (2017) criteria B1b(i,ii,iii). It is endemic to the Serra do Tabuleiro, southern Brazil, known for few collections from only one locality. Its area of occupation (AOO) is 4 km ² and the extent of occurrence (EOO) is less than 2 km ². Despite the area in which it occurs is included in a conservation unit, the habitat is endangered by low extension of occurrence, presence of cattle and a gradual increase of people visiting the place for leisure.

Etymology: —the species is named in honor of the botanist João Iganci, a great researcher on the evolution of highland ecosystems and distribution of endemic species in southern Brazil.

Phenology: —flowers and fruits from July to August.

Paratypes: — BRAZIL. Santa Catarina: São Bonifácio, Serra do Tabuleiro , 27°49’19.5”S 48°53’50.9”W, 28 July 2017 (stam. fl.) J.Külkamp, F.Gonzatti & E.Valduga 234a ( ICN!, RB!) ; São Bonifácio, Serra do Tabuleiro , 27°49’19.5”S 48°53’50.9”W, 28 July 2017 (pist. fl.) J.Külkamp, F.Gonzatti & E.Valduga 234b ( ICN!) ; São Bonifácio, Serra do Tabuleiro , trilha para o Morro das Pedras , 27°49’12.6”S 48°53’57”W, 1132 m elev., 19 August 2017 (stam. fl.) C.Rabuske, C.C.Alff & L.Nicoleite 273, 274 ( ICN!) ; São Bonifácio, Serra do Tabuleiro , trilha para o Morro das Pedras , 27°49’12.6”S 48°53’57”W, 1132 m elev., 19 August 2017 (pist. fl.) C.Rabuske, C.C.Alff & L.Nicoleite 275, 276 ( FLOR!) ; São Bonifácio, Serra do Tabuleiro , trilha para o Morro das Pedras , 27°49’12.6”S 48°53’57”W, 1132 m elev., 19 August 2017 (stam. fl.) C.Rabuske, C.C.Alff & L.Nicoleite 277, 280 ( HUCS!) ; São Bonifácio, Serra do Tabuleiro , trilha para o Morro das Pedras , 27°49’12.6”S 48°53’57”W, 1132 m elev., 19 August 2017 (pist. fl.) C.Rabuske, C.C.Alff & L. Nicoleite 278 ( MBM!) .

Comments: — Valeriana iganciana occurs in highland grasslands of shallow granitic soil, under rocky and humid outcrops. Its occurrence predominates in slopes facing south, sheltered from the incidence of strong winds, common in the high altitude region of Serra do Tabuleiro, which reaches more than 1200 meters of elevation. The area of the Serra do Tabuleiro State Park consists of a large heterogeneity of vegetation formations of forest-grasslands mosaic. In the higher areas there is grassland vegetation that, together with the Ombrophilous Mixed Forest dominated by Araucaria angustifolia (Bertol.) Kuntze (1898: 375) , forms a still very conserved vegetation mosaic in contrast with the anthropic influences of the lowlands. As the altitude decreases, the species that characterize the Ombrophilous Dense Forest become more abundant and the rural areas become more frequent. In the Serra do Tabuleiro, the highland grasslands are isolated in patches between the Araucaria forest. These conditions of altitude and isolation promote a differentiated and botanically poorly sampled micro-habitat that is conducive to the occurrence of endemic species unknown to science ( Iganci et al. 2011). Despite the special biotic and abiotic conditions of highland grasslands of Serra do Tabuleiro, its flora remains poorly studied.

Figures

FIGURE 1. Illustration of Valeriana iganciana. A. Habit; B. Detail of inflorescence; C. Staminate flower; D. Staminate flower, opened; E. Pistillate flower on immature fruit; F. Pistillate flower, opened; G. Leaf in adaxial view with apex detail in abaxial view. H. Fruit in adaxial view; I. Fruit in abaxial view; J. Fruit in apical view; K. Fruit in transverse view.; l = locule, p = parenchymatous tissue, s = seed (Vouchers: A, B, C, D—C.Rabuske, C.C.Alff & L.Nicoleite 279; E, F, G, H, I, J, K—C.Rabuske, C.C.Alff & L.Nicoleite 278). Drawn by João Iganci.

FIGURE 2. Valeriana iganciana. A. Habitat; B. Habit; C. Leaf in adaxial view; D. Staminate flowers; E. Pistillate flowers with immature fruits. Photos by Cassio Rabuske da Silva.

FIGURE 3. Distribution map of Valeriana iganciana showing the only locality where the species was collected until now, in the Santa Catarina state, Brazil.