Cattleya ninae Menezes, Giordani, Mendes & Corrêa, 2025

Menezes, Euler Da Luz Fernandes, Giordani, Samuel Cunha Oliveira, Mendes, Jone Clebson Ribeiro, Abreu, Caíque Menezes De, Filho, Paulo Roberto De Carvalho Spínola- & Viotti, Julia, 2025, Cattleya ninae, a new species of Orchidaceae (Laeliinae) in the northern Espinhaço region of Minas Gerais, Brazil, Phytotaxa 693 (2), pp. 146-156 : 150-154

Cattleya ninae Menezes, Giordani, Mendes & Corrêa , sp. nov.

( Figures 1 and 2 ).

Type:— BRAZIL. Minas Gerais: Itacambira, Beira da rodovia. 1270 m a.s.l., January 2019, rupiculous on dry rocks with sparse vegetation, E.L.F. Menezes, C.O. Giordani & J.C.R. Mendes 406 (holotype: HDJF 8049 !; isotypes: DIAM, BHCB)

Cattleya ninae differs from C. bradei and C. esalqueana primarily by its smaller plant size, shorter pedicel, and smaller flowers. C. ninae has obovoid pseudobulbs with two internodes, a pedicel of 1.9–2.1 cm, and flowers with a 2.0– 2.5 cm diameter. In contrast, C. bradei has elongated, semi-terete pseudobulbs with three internodes, a pedicel of 3.2–3.6 cm, and flowers of 2.0– 2.5 cm in diameter, while C. esalqueana features elongated, semi-terete pseudobulbs with three internodes, a pedicel of 3.8–4.1 cm, and larger flowers with a 3.0– 3.6 cm diameter. Additionally, the lip of C. ninae is smaller, with a median lobe measuring 2.9–3.1 x 3.0– 3.1 mm, compared to the larger lip of C. bradei and C. esalqueana . The rachis of C. ninae is 2.0– 2.5 cm long, significantly shorter than the 4.5–6.0 cm rachis of C. esalqueana , and slightly shorter than the 3.2–3.6 cm rachis of C. bradei .

Description: — Plant saxicolous, caespitose, 3.0‒7.0 cm. Roots white, glabrous, flexuous, 2.0‒ 2.5 mm diameter. Rhizome inconspicuous. Pseudobulbs 20‒25 × 10‒14 mm, obovoid, green, often pigmented with purple, smooth, articulate, 2 internodes, unifoliate, dressed with papery, deciduous sheaths. Leaves green, often pigmented with purple, elliptic, erect, coriaceous, fleshy, navicular, apex acute, 16‒18 × 8‒9 mm. Spathe triangular, conduplicate, apex acute, 5‒6 × 3‒4 mm. Inflorescence apical, erect, 53 mm length, with 1‒2 flowers, rachis green, cylindrical, 20‒23 mm length. Floral bract triangular, acute, 4.0‒ 4.2 mm length. Pedicellate ovary clear green, but dark green inside the ovary, slightly clavate, 1.9–2.1 × 1.0‒ 1.1 mm, and 1.8‒1.9 mm width near the flower. Flowers yellow, lip darker yellow, scented, simultaneous, ca. 25 mm width in natural position. Dorsal sepal lanceolate, apex acuminate, 12‒13 × 5‒6 mm. Lateral sepals oblong-lanceolate, slightly falcate, apex acuminate, 12‒14 × 6‒7 mm. Petals oblong-lanceolate, apex acuminate, 13‒14 × 5.0‒ 5.5 mm. Lip moderately recurved, deeply 3-lobed, ovate when flattened, 9.0‒9.5 × 7.0‒ 7.5 mm, 2 midline, longitudinal, linear carinas, chestnut-red colored at the base then transitioning to yellow; lateral lobes individually reniform when flattened, 6.0‒6.5 × 3.5 mm; median lobe with wavy margins, slightly curved backwards, sub-quadrate when flattened, 2.9‒3.1 × 3.0‒ 3.1 mm width. Column concave, 6.5‒6.6 mm length, sub-rectangular in a profile view. Stigmatic cavity cordiform, 1.0‒ 1.1 mm length. Anther cuculiform, off-white, multilocular, 1.0‒ 1.1 mm width. Pollinia 8, waxy, discoid, laterally flattened, yellow.

Distribution and ecology: —So far, we know C. ninae occurs only in Itacambira, Minas Gerais, and there are only approximately 50 known specimens of the species, typically associated with rocky outcrops with sparse shrubby vegetation ( Figures 1 and 3 ). For this reason, we believe C. ninae is endemic to these isolated rocky outcrops. Exploring the area further is crucial to determine whether other populations exist. Flowering was observed between January and February.

Etymology:—The specific epithet is dedicated to Nina Rodrigues da Silva, an orchid grower and resident of Itacambira, Minas Gerais, Brazil.

Conservation status:— Given the incomplete information on its distribution, we have classified the new species as Data Deficient (DD) ( IUCN 2022). Nonetheless, the population observed occurs outside any protected area, and this vulnerability should be taken into account in future status assessments.

Taxonomic discussion: — Cattleya ninae is a saxicolous species of small plants, typically reaching heights between 3‒7 cm. They have small, obovoid pseudobulbs and thick leaves because they grow in stony and dry environments associated with organic matter. Usually, these plants are found at the foot of other individuals or near sparse vegetation in their habitat. This species belongs to C. sect. Parviflorae, consisting mainly of small plants found in Diamantina , Minas Gerais, Brazil ( Antonelli et al. 2010, van den Berg 2014). Similar plants in this category include C. bradei and C. esalqueana , both occuring sympatrically in this same rocky region of Minas Gerais.

The distribution of distances between the coincidence frequencies of C. ninae and C. esalqueana was 0.0, while the distance between C. ninae and C. bradei was 0.06, and between C. esalqueana and C. bradei , 0.31. Considering their morphological and reproductive characteristics, these results showed that C. ninae and C. esalqueana exhibit higher similarity, while C. ninae and C. bradei are phenotypically close, but not identical. On the other hand, Cattleya esalqueana and C. bradei are less similar than the other pairs ( Figure 6 ).

The cophenetic correlation between the species was 0.65, with a moderately strong p-value of 0.35, indicating an agreement between the phenotypic data and the constructed similarity tree ( Figure 6 ). Results showed two subgroups, with C. ninae and C. esalqueana phenotypically closer than C. bradei . According to the cutoff criterion, K = 1.25, the species exhibited a high degree of similarity, which suggests that the phenotypic differences between them are not significant enough to create distinct clusters ( Figure 6 ).

The phenotypic distribution of the specimens based on the coincidence distances via PCoA indicated a significant result of 0.048 (PCoA1). At the same time, the other coordinates (PCoA2, PCoA3) showed values very close to zero: 1.21e- 17 and 0, respectively. In this sense, the first principal coordinate primarily explains the phenotypic variation between the species ( Figure 7 ). The vectors associated with these principal coordinates revealed the projections of the species in the main directions of phenotypic variation. C. ninae showed a value of -0.003 for PCoA1, C. esalqueana had -0.154 for PCoA1, and C. bradei exhibited 0.158, all with null projections for PCoA2 and PCoA3, denoting, once again, C. ninae is very close to C. esalqueana , while C. bradei is more distant regarding phenotypic variation.

Cattleya ninae distinguishes itself by exhibiting obovoid pseudobulbs with two internodes (as opposed to elongated, semi-terete pseudobulbs with three internodes in C. esalqueana and C. bradei ). Additionally, the rachis is notably shorter, measuring between 2.0‒ 2.5 cm length, often even smaller than the length of the pedicel (in contrast to 5–7 cm in C. bradei and 4.5‒6.0 cm in C. esalqueana ). The pedicel of C. ninae measures 1.9–2.1 cm in length (in contrast to 3.2–3.6 cm in C. bradei and 3.8–4.1 cm in C. esalqueana ) ( Figure 8 ).

Furthermore, C. ninae has smaller yellow flowers with a diameter of 2.0– 2.5 cm, similar to some of the flowers of C. bradei , but unlike the golden-yellow flowers of C. esalqueana , which have a diameter of 3.0– 3.6 cm. The tube of the lateral lobes in C. ninae is also smaller, measuring 0.25‒0.28 cm (compared to 0.41‒0.46 cm in C. bradei and 0.40‒0.45 cm in C. esalqueana ). These differences are due to the position of the column of C. ninae , which creates a smaller opening angle of 4.6º compared to 10º in C. bradei and 13.7º in C. esalqueana ( Figure 4 ). Differences in floral architecture may influence floral orientation and accessibility, affecting pollinator interactions and likely reflecting evolutionary adaptations to specific pollinators or ecological niches ( Smidt et al. 2006). Smidt et al. (2006) demonstrated that smaller pollinators visiting Cattleya tenuis flowers were unable to remove the pollinarium. Further studies are required to test if a wider column opening angle might have an analogous effect on pollinarium removal.

We conclude that, although the proposed new taxon is highly similar to C. esalqueana and C. bradei , it more closely resembles C. esalqueana from a morphological perspective. Ecological or evolutionary factors may shape the observed phenotypic differences among these species. While we propose the new taxon conservation status as Data Deficient (DD), the only observed population occurring outside any protected area points to its potential vulnerability, which should be carefully considered in future status assessments.

Identification key for Cattleya ninae and species with similar phenotype

1. Pseudobulbs obovoid with 2 internodes ....................................................................................................................... Cattleya ninae

- Pseudobulbs elongated and semi-terete with 3 internodes .................................................................................................................2

2. Short inflorescence peduncle............................................................................................................................... Cattleya esalqueana

- Inflorescence peduncle well above the leaves............................................................................................................. Cattleya bradei

Figures

FIGURE 1. Cattleya ninae in its habitat.

FIGURE 2. Cattleya ninae A. Habit; B–D. Flower; E. Pedicellate ovary + column, with lip (left); F. Perianth; G. Lip in exploded planar view; H. Bracts involving the pedicel; I. Column in side and ventral views; J. Anther cap; K. Pollinarium. (Photos by Mauro Sérgio Rosim).

FIGURE 3. Geographical location of Cattleya ninae within the Espinhaço Range Biosphere Reserve (ERBR).

FIGURE 4. Comparison of the column in Cattleya ninae and similar species. A. C. ninae; B. C. bradei; C. C. esalqueana.

FIGURE 6. Frequency distribution of coincidence among Cerrado species (left) and dendrogram (right) obtained using Ward’s method, based on dissimilarity measures among Cattleya ninae; Cattleya esalqueana; and Cattleya bradei. We estimated the cophenetic correlation coefficient at 0.65 using the Mantel test (p-value: 0.65).

FIGURE 7. Principal Coordinate Analysis (PCoA) of phenotypic distances between Cattleya species, 1: C. ninae; 2: C. esalqueana; 3: C. bradei.

FIGURE 8. Comparison of the floral pedicel in Cattleya ninae and similar species. A. C. ninae; B. C. bradei; C. C. esalqueana.