Amoana latipetala Leopardi & Hágsater, 2012

Leopardi, Carlos, Carnevali, Germán & Romero-González, Gustavo A., 2012, Amoana (Orchidaceae, Laeliinae), a new genus and species from Mexico, Phytotaxa 65 (1), pp. 23-35 : 30-32

Amoana latipetala Leopardi & Hágsater , sp. nov. ( Figs. 3A–B ).

Species haec Amoanae kienastii valde affinis, ab hac flore robustiore, petalis sepalisque brevioribus (1.6 cm vs. 2–2.3 cm) et latioribus (0.7 cm vs. 0.3–0.4 cm), labello orbiculari-elliptico (in A. kienastii oblongo-obovato ) imprimis differt.

Type: ⎯ Mexico. Without locality, Bussey s.n. sub Hágsater 9923 (holotype: AMO!) .

Inflorescence 12–13 cm long, apparently simple (only known from a fragment); peduncle bracts 2.0– 2.5 cm long, narrowly elliptic. Floral bracts 0.4–0.5 × 0.2–0.3 cm, elliptic-lanceolate, relatively conspicuous (1/3–1/2 the length of the pedicellate ovary), spreading, papyraceous upon drying. Flowers pale pink or lilac, darker at apices of the perianth segments and callus, lip with five veins, central one darker; sepals lanceolate, acutely obtuse, ca. 1.6 × 0.7 cm; petals elliptic-oblanceolate, acute, ca. 1.6 × 0.7 cm; lip basally adnate to the column (for about 1/3 of its length), trilobed, total length ca. 1.6 cm; lateral lobes spatulate-obovate, rounded, irregularly notched at apex, ca. 1.1 × 0.1 cm at its base, ca. 0.6 cm wide near its apex; midlobe clawed, suborbicular to broadly elliptic, rounded, ca. 1.3 × 1.1 cm, the margins somewhat undulate; callus on the claw and base of mid lobe, oblong, distantly forming 2 acute, ascending, finger-like processes, the midlobe with 5 keeled veins; column greenish white, slender, clavate, sharply bowed in the middle, ca. 1 cm long, the middle tooth obtuse, denticulate, shorter than the lateral teeth which are surpassed by the anther, and with red spots at sides of the column wings; anther pale yellow. Capsule not seen.

Etymology: ⎯The specific epithet refers to the wider petals in comparison with those of Amoana kienastii .

Distribution and ecology: ⎯The species is known from a single collection of uncertain origin; it is suspected to have come from Oaxaca or Guerrero.

Discussion: ⎯This species is easily distinguished from Amoana kienastii by its more robust flowers and lanceolate tepals, which are wider (ca. 0.7 cm) and shorter (ca. 1.6 cm) than those of A. kienastii (0.3–0.4 × 2.0– 2.5 cm). The lip of A. latipetala is also different from that of A. kienastii ; it is orbicular-elliptic, not oblong-obovate as in A. kienastii .

IUCN Conservation assessment: ⎯ CR. Amoana latipetala meets criteria B1a and B2a of the IUCN. The species is known from a single collection of uncertain provenance (Oaxaca or Guerrero).

MER Conservation assessment : ⎯ P (in danger of extinction). Amoana latipetala is known from only one specimen of uncertain provenance (possibly from Oaxaca or Guerrero), thus most likely occurring in less than 5% of the Mexican territory. Judging from the biology of its sister species and the fact that it is known from a single collection, it seems safe to assume that is rare and grows at low population densities. Upon assessing the conservation status of this taxon against MER criteria, it scores 14 points.

Figures

FIGURE 3: Amoana. A–B. Amoana latipetala. B. Drawing of sepals, petals, and lip. C–D. Amoana kienastii. C. Flower. D. Lateral view of the labellum and column; note two digitiform processes just behind the column. A–B, based on the holotype; C–D, from E. Greenwood Archive at AMES.