Cleistes pallida Funez & Pansarin, 2018

Funez, Luís Adriano & Pansarin, Emerson Ricardo, 2018, Cleistes pallida (Orchidaceae Vanilloideae): a new species from South Brazil, Phytotaxa 349 (1), pp. 61-66 : 62

Cleistes pallida Funez & Pansarin , sp. nov. ( Figs. 1–2 )

Type: — BRAZIL. Santa Catarina: Rodeio: 22 February 2017, L.A. Funez et al. 6059 (holotype FURB-52732!).

Diagnosis: —The new species, Cleistes pallida , differs from Cleistes mantiqueirae Reichenbach & Warming (81: 1881), by its smaller flowers, and its deltoid apical lobe of the labellum with a longer labellum isthmus. In C. mantiqueirae the flowers possess a rounded apical lobe with a short labellum isthmus.

Description: —Herbs 13–84 cm tall. Roots tuberous. Stems 1 ‒ 5 mm diam., fistulose, glaucous. Leaves 1.0 ‒ 6.6 × 0.4 ‒ 1.2 cm, lanceolate to elliptic-lanceolate, erect, flat, concave or conduplicate, glaucous. Apical leaves smaller than the median ones. Basal leaves reduced to small sheaths, elliptic, amplexicaul, glaucous. Inflorescence racemose with 2–8 resupinate flowers, one per node. Flowers predominantly pale-pink, with an abscission layer between perianth and ovary. Ovary + pedicel 1.5 ‒ 3.2 cm long. Sepals 1.8 ‒ 2.6 × 0.2 ‒ 0.4 cm, lanceolate to linear-lanceolate, pale-pink to whitish, with an acute apex. Petals 1.9 ‒ 2.1 × 0.5 cm, elliptic to linear-lanceolate, pale-pink to whitish, with an acute apex and a darker pink coloration toward the apex. Labellum 1.9 ‒ 2.2 × 0.6 ‒ 0.7 cm, 3-lobed, oblanceolate, whitish toward the basal portion, pale-pink to the apex, veins inconspicuous, visible only in sicco; nectariferous glands 1 mm, spherical. Longitudinal labellar crest yellow, with very short papillae; papillae bright yellow just on the apical portion; lateral lobes falcate, apex acute; apical lobe unguiculate, weakly distinct from the isthmus, almost straight, isthmus 4.5 ‒ 5 mm long., rectangular, apical portion deltoid. Column 1.0 ‒ 1.3 cm long., straight to slightly recurved, whitish; stigma 4 ‒ 5 mm long, ovate, flat; anther pale pink, apex truncate; pollinia 2 mm long. Fruits 2.5 × 0.3 cm, linear or conical, narrowed towards the base. Plant nigrescent when dried.

Etymology: —The epithet is a reference to the pale coloration of the flowers.

Distribution and habitat: — Cleistes pallida is known for the type-locality, an area of less than 25 m ², located on a single mountain, between the municipalities of Benedito Novo and Rodeio, state of Santa Catarina, southern Brazil. ( Fig. 3 ). This species occurs on open vegetation of hilltops, in Vale do Itajaí region ca. 800–900 m elevation. The vegetation where C. pallida has been found is naturally more open than the surrounding vegetation. The presence of some ruderal species of grasses and Gleicheniaceae ferns is an indicative of anthropogenic disturbance in this area. ( Fig. 4 ).

Conservation status: —Critically endangered (CR–B2a,b[iii]), according the IUCN criteria.The habitat of Cleistes pallida has been strongly impacted by human activities. In 2014 the biggest zipline of Americas was constructed in the area, with negative impacts on the natural vegetation.

Although plants of Cleistes pallida occur out of a conservation unit, the mountain of the type-locality of Cleistes pallida is priority for preservation, with some endangered botanic species, such as the newly described endemic species Siphocampylus baccae Funez & Hassemer (2016: 244–246) and S. sevegnaniae Funez & Hassemer (2016: 248–250) .

Comments: — As presented here, flower features of Cleistes pallida is closely related to to Cleistes mantiqueirae , a species that occurs in open fields and rocky outcrops in central western and southeastern Brazil. In addition, Cleistes ramboi Pabst (130: 1953) is similar to C. pallida in the colour of its flowers and shape of the labellum, with an isthmus weakly distinct from the apical portion of apical lobe in C. ramboi . However, C. pallida is easily distinguishable from C. ramboi by the inconspicuous veins on the labellum of the former. Furthermore, C. pallida differs from C. ramboi with regards to the central crest of the labellum. In C. pallida the central crest is covered with yellow papillae, while in C. ramboi the labellar crest is covered with white fimbriae. Cleistes ramboi is a species that occurs from Bahia to Rio Grande do Sul, from northeastern to southern Brazil.

The size of flower structures also are important features differing Cleistes pallida from C. mantiqueirae and C. ramboi ( Table 1). The sepals of Cleistes pallida measure 2.6 × 0.2 cm, whereas in C. mantiqueirae and C. ramboi the sepals measure more than 3.0 × 0.5 cm. This same proportion in size can be recorded in the size of petals and labellum ( Table 1).

Additional material examined (paratype): — BRAZIL. Santa Catarina: Rodeio: 19 February 2015, Funez 4252 (FURB 47187).

Figures

FIGURE 1. Cleistes pallida Funez & Pansarin.A. Habit. B. Detail of a leaf. C. Flower in front view.D. Flower in lateral view.E. Perianth. F. Column in lateral view. Bars: A= 5 cm; B‒F = 1 cm.

FIGURE 3. Distribution map of Cleistes pallida.

FIGURE 4. Habitat of Cleistes pallida.