Cattleya

Neto, Vitorino Paiva Castro, Motte, Denis & Dubuisson, Jean-Yves, 2012, Cattleya × itabapoanaensis (Orchidaceae), a new natural hybrid from Rio Janeiro State (Brazil), Phytotaxa 50 (1), pp. 64-68 : 64-68

Cattleya × itabapoanaensis V.P. Castro & D. Motte , nothosp. nov., Fig. 1 & Fig. 3A

Flowers with intermediate shape and coloration between those described for Cattleya porphyroglossa Linden & Reichenbach and Cattleya harrisoniana Bateman ex Lindley.

Type:— BRAZIL. Rio de Janeiro: Bom Jesus de Itabapoana district, in a gallery forest around the Itabapoana River, 350 m, December 2011 (flowered in cultivation at Sávio Domingos Caliman greenhouses at Venda Nova do Imigrante ), Vieira s.n. in Castro 0155 (holotype SP) .

Epiphytic herb. Rhizomes 1.5–2.0 cm long, roots 2.5–3.0 mm in diameter. Pseudobulbs 17.0–35.0 × 1.0– 1.5 cm, cylindrical and homoblastic. Leaves 2(3), apical on pseudobulbs, 12–13 × 4–5 cm, elongate and elliptic. Inflorescences a short raceme, 8–9 cm long with 1–3 flowers emerging from a single spathe, 5.0–5.5 × 1.0– 1.3 cm, floral bracts present but inconspicuous. Flowers 8.5–9.0 cm in diameter; ovary cylindrical, 4.0–5.0 × 0.5–0.6 cm, fused with the short pedicel; sepals three, orange-pink in colour, dorsal sepal oblong-lanceolate 6.5–6.8 × 1.7–1.9 cm, lateral sepals falciform, 5.0–5.2 × 2.8–2.9 cm; petals two, orange-pink to light pink marginally, elongate-elliptic with unguiculate bases 6.5–6.8 × 2.7–2.9 cm; labellum trilobed, lateral lobes white with pink margins, well developed and fully overlapping column, trapezoidal, 3.0–3.2 × 4.7–4.8 cm, median lobe reniform 1.7–1.8 × 3.0– 3.2 cm, bases orange with purple veins and undulate white margins; column triangular, curving forward apically, ventrally concave, 2.0– 2.2 cm long, pollinia four and parallel, yellow, 2 mm long.

Distribution and habitat:— Brazil; endemic. The plant was collected in a gallery forest around the Itabapoana River at Bom Jesus de Itabapoana district, State of Rio de Janeiro ( Fig. 2 ). The plant grew as an epiphyte in a wet area at low elevation. Etymology:— The plant was named for the Itabapoana River, State of Rio de Janeiro ( Brazil).

Phenology:— December.

The specimen clearly displays numerous features shared with its putative parent species, supporting its hybrid origin. Cattleya harrisoniana flowers are typically pink ( Fig. 3B ), whereas C. porphyroglossa flowers exhibit an orange perianth (except for the labellum, which is purple; Fig. 3C ). The orange-pink coloration of the sepals and lateral petals of C. × itabapoanaensis likely results from a mixture of the two parental colorations. Cattleya × itabapoanaensis also displays the globe-shaped sepals and lateral petals, especially the falciform lateral sepals, of C. porphyroglossa . Furthermore, the lip appears to be intermediate in form between the large white and yellow smooth lip of C. harrisoniana and the small purple rough one of C. porphyroglossa .

Cattleya harrisoniana has been previously implicated in the formation of six natural hybrids: C. × lucieniana Reichenbach (1885: 456) with C. tigrina Richard ex Beer (1854: 215) , C. × calimaniana Campacci (2007a: 28) with C. schofieldiana Reichenbach (1882: 808) , C. × duveenii Pabst & Mello (1977: 184) with C. guttata Lindley (1831: t. 1406); C. × brasiliensis Klinge (1899: 135) with C. bicolor Lindley (1836: sub t. 1919); C. × kaustkyi Pabst (1975: 50) with C. warneri Moore ex Warner (1862: t. 8); and C. × venosa Rolfe (1894: 132) with C. forbesii Lindley (1821 : sub. t. 37). Except C. × kautskyi , all these hybrids also involve bifoliate taxa belonging to subgenus Intermediae. The unifoliate C. warneri combined with C. porphyroglossa would produce the natural hybrid C. × schunkiana Campacci (2007b: 142) . Thus, C. × itabapoanaensis would be the second reported natural hybrid involving C. porphyroglossa .

In its native area, C. porphyroglossa usually blooms at the beginning of summer from October to November, whereas C. harrisoniana usually begins flowering in January. Their phenologies are not overlapping, which should prevent hybridization and reinforce pre-zygotic isolation. However, exceptionally late C. porphyroglossa flowering and early C. harrisoniana can result in flowers of both species being present at the same time (e.g. in December). Hybridization, although infrequent, is nevertheless possible. In addition, flowering of the hybrid in December is in accordance with the possible phenology overlap. Because this hybrid is based on a single specimen that flowered in a greenhouse, additional field investigations are needed to determine its precise natural distribution and stability in nature.

Figures

FIGURE 1. Cattleya ×itabapoanaensis. a. Habit. b–e. Detail of perianth (b: dorsal sepal, c: lateral petal, d: lateral sepal, e: labellum). f. Detail of column, side view (right), ventral view (left). g. Anther cap with pollinia intact. h. Pollinia and caudicles. (Drawing by V.P. Castro)

FIGURE 2. Map for Cattleya × itabapoanaensis in Brazil at Bom Jesus do Itabapoana, Rio de Janeiro State. (Drawing by L. Echternacht-Andrade)

FIGURE 3. Comparison of Cattleya × itabapoanaensis and putative parents. A. Cattleya × itabapoanaensis. B. Cattleya harrisoniana. C. Cattleya porphyroglossa. (Photographs by V.P. Castro)