Dryadella catharinensis Imig, Mancinelli & E.C.Smidt
|
publication ID |
https://doi.org/ 10.11646/phytotaxa.508.2.9 |
|
persistent identifier |
https://treatment.plazi.org/id/E60C7709-FF86-FFF1-3FE4-FCA1FE29F42C |
|
treatment provided by |
Marcus |
|
scientific name |
Dryadella catharinensis Imig, Mancinelli & E.C.Smidt |
| status |
|
Dryadella catharinensis Imig, Mancinelli & E.C.Smidt View in CoL sp nov. ( Figs. 1–2 View FIGURE 1 View FIGURE 2 )
Type:— BRAZIL. Santa Catarina: Joinville, Morro do Tromba , 03 September 2009, [fl.], W . S . Mancinelli 1007 (holotype JOI) .
Diagnosis: —The new species is morphologically similar to Dryadella susanae ( Pabst 1976: 68) Luer (1978: 371) but can be distinguished by the larger vegetative size, the narrow and suberect leaf, the yellow flower, the sepals with slightly denticulate margins, the petals with an obtuse apex and cuneate lip, with denticulated margins and the presence of ring callus in the median portion of the claw.
Description:— Epiphytic herb, caespitose, minute, 16–23 mm tall. Roots thick, 2–3 at each rhizome node, 0.5–0.7 mm diameter. Rhizome 1–1.5 mm between the internodes. Ramicaul 1.5–2 mm long, suberect, covered by two paleaceous, deltoid sheaths, truncated at the base, obtuse, mucronate, entire, 0.8–1.2 × 0.6–0.8 mm. Leaf dark green on the adaxial side and vinaceous on the abaxial side, coriaceous, narrowly elliptic, 13–19.5 × 2.1–3.3 mm; petiole 1–1.5 mm long; blade suberect, retuse, entire. Inflorescence a successive, single-flowered, congested raceme; bearing two pale, imbricate, mucronate, entire basal bracts; peduncle 5.5–8.5 mm long; pedicel plus ovary light green with purple dots, slightly trialate, 0.8–1.3 mm long. Flower resupinate; dorsal sepal pale yellow, densely dark-purple spotted, ovate, inflexed, three-veined, carinate, 4.5–5.2 × 2–2.5 mm, base truncate, connate 0.5 mm with the lateral sepals forming a short sepaline cup, obtuse, entire; lateral sepals light pale yellow, with sparse light purple spots at base, ovate, threeveined, asymmetrical, 3.3–3.7 × 1.8–2.3 mm, connate at the truncate base, short caudate, margin slightly denticulate, subacute, transversal callus purple; petals dark-yellow, red-spotted, rhomboid, two-veined, asymmetrical, 1.0–1.4 × 1.3–1.5 mm, base truncate, obtuse, superior margin erect, lobe acute, slightly projected forward; inferior margin excavated, lobe acute; lip dark yellow, unguiculate; claw 0.7–0.8 mm, bilobed at base, caniculate with a transversal annular callus in the median portion; blade cuneate, three-veined, 1.8–2.1 × 1.5–1.6 mm, base with two lateral, acute retrorse lobes, a pair of lamellar callus at the base; apex reflexed, obtuse, denticulated; column dark-yellow, red in the ventral margin, 1.5–1.7 mm long, curved, winged on the distal half, acute-toothed at winged base; apex minutely denticulate, foot equally long; anther red, apiculate; pollinarium not seen. Fruit not seen.
Additional material examined (paratypes):— BRAZIL. Santa Catarina: Corupá, Bairro Izabel , 01 September 2020, [fl.], D. C . Imig 656 ( UPCB). Joinville, Serra Dona Francisca , next to Estrada Piraí , 29 August 2020, fl., W . M . Mancinelli & D. C . Imig 1591 ( MBM) .
Discussion: — The tiny Dryadella catharinensis is similar to D. susanae , they share the ovate lateral sepals with short caudate apex. The new species may be distinguished vegetatively in the larger size of the plant 16–23 mm (vs. 10– 13.5 mm) and in the larger 13–19.5 × 2.1–3.3 mm (vs. 3–5 × 1.5–3 mm), narrowly elliptical, suberect and petiolate leaves (vs. leaves broadly elliptical, prostrate and sessile). Florally, D. catharinensis is distinguished by the yellow (vs. dark red) flower, the dorsal sepal 4.5–5.2 mm long (vs. 3.8–4.0 mm), ovate, obtuse and thin (vs. triangular-ovate, acute, thickened), the lateral sepals with the margin slightly denticulate (vs. margin entire), the 1.0– 1.4 mm long petals (vs. petals 1.5 mm) and the larger lip blade 1.8–2.1 × 1.5–1.6 mm (vs. lip blade 1.5 × 1.4 mm), cuneate, with margins denticulated, and a ring callus in the median portion of the claw (vs. obovate, margins entire, without callosities in the claw).
In terms of geographic distribution, D. susanae is currently restricted to the state of Espírito Santo, Northern Atlantic Forest super-bioregion ( Reginato & Michelangeli 2020) in the Serra do Mar Area of Endemism ( Peres et al. 2020), where it is found growing at elevations between 800–1000 m alt. Dryadella catharinensis is restricted to the Santa Catarina state, Southern Atlantic Forest/ Paraná Forest super-bioregion ( Reginato & Michelangeli 2020), in the Paraná / Araucária Area of Endemism( Peres et al. 2020) at 200–300 m alt. (see Fig. 3 View FIGURE 3 ).
Dryadella catharinensis was misidentified as D. aviceps in Mancinelli & Esemann-Quadros (2016) despite significant morphologically differences. Dryadella aviceps has its southern distribution limit west of the state of Paraná (Foz do Iguaçu and Guaíra) and extends to the region of the Ybycuí National Park, in Minas Kue, Paraguay. There is no record of D. aviceps in the Santa Catarina state ( Luer 2005, CRIA 2016, Imig et al. 2020). In southern Brazil, three other species o f Dryadella have been registered. Dryadella lilliputiana can be easily recognized by the terete, rather than flat, leaves. Dryadella catharinensis differs from D. edwallii and D. zebrina in the smaller plants (<3 cm); D. edwallii has narrowly elliptic, green leaves with purplish nuances and a dorsal sepal with a clavate tail and D. zebrina has elliptical, green leaves and a dorsal sepal with a slender tail.
Distribution, habitat and phenology:— Dryadella catharinensis was found in Joinville and Corupá, northnortheast of the Santa Catarina state, at an elevation between 200–300 m in the Dense Ombrophilous submontane rainforest. In Joinville, it occurs in the Morro da Tromba (type locality) and Morro Pelado, both within the Serra Dona
Francisca Environmental Protection Area (APA) with an extension of 401.77 km 2. Few individuals were found at both sites, growing at 2–3 m from the ground next to bifurcations of the central stem of the phorophyte. Flowering was registered from August to October.
Etymology:—Named after Santa Catarina State, where the new species was collected.
Conservation status:—According to the Categories and Criteria of IUCN Red List (2019), Dryadella catharinensis should be assigned a conservation status of “Endangered” [EN B1ab(i,iii)+2ab(ii,iii)]. The geographic range where the new species was found is in a fragmented area of the Atlantic Rainforest, north-northeast of the Santa Catarina state. The two localities (three collection points) are in the same habitat, at a distance of only ca. 40 km. The Extent of Occurrence (EOO) is estimated to be 66,7 km 2, whereas its Area of Occupancy (AOO) is 8 km 2. In several excursions to the type locality and surrounding areas, very few specimens (>10) were located in a large area, indicating a low density of the known populations. Recently, the epiphytic flora of Santa Catarina State was inventoried ( Vibrans et al. 2013), and this species was not sampled, which evidences its rarity. Dryadella catharinensis is under numerous threats, including deforestation, overgrazing, habitat fragmentation, random cutting, human interference, and climate change. The northern region of the State of Santa Catarina is under anthropic pressure, with the replacement of native vegetation by invasive species of Pinus spp. and Eucalyptus spp. , which degrades the quality of the adjacent forest. Recent problems with fires arising from human activities have increased, including in the Morro da Tromba and the Morro Pelado, in Joinville, causing severe environmental damage to the type population habitat.
Further fieldwork is needed to locate additional populations and increase the extent of occurrence and occupation area. The study of floral biology, the phorophyte preference, and mycorrhizal associations are also needed to conserve this tiny, rare orchid.
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.