Prescottia densiflora (Brongn.) Lindl., Ann. Mag. Nat. Hist.

Azevedo, Cecília Oliveira De, Berg, Cássio Van Den & Barros, Fábio De, 2014, A revision of Prescottia (Orchidaceae: Orchidoideae, Cranichideae), Phytotaxa 178 (4), pp. 233-286 : 243-250

2. Prescottia densiflora (Brongn.) Lindl., Ann. Mag. Nat. Hist. 1, 6: 52. 1840. [ Cogniaux 1895, Brade & Pabst 1952, Pabst & Dungs 1975, Azevedo & van den Berg 2007a]; basionym: Decaisnea densiflora Brongn., Voy. Coq. Bot. 192: 39. 1829. [ Lindley 1840b, Cogniaux 1895, Hoehne 1945, Azevedo & van den Berg 2007a, Macagnan et al. 2011, Govaerts 2014] Type:— BRAZIL. Santa Catarina, Brongniart s.n. (lectotype K-L!; isolectotype P!, selected by Azevedo & van den Berg 2007a). Fig. 15 .

Terrestrial herbs. Leaves (3–)5–8; basal to rosulate; sessile to pseudopetiolate; petiole 1.0–2.0 cm long, green, blade 3.0–6.0(–8.0) × 1.8–3.0(–4.8) cm, elliptic to lanceolate, apex acute, base attenuate to obtuse, green, margin entire. Inflorescence 50–150-flowered, flowers overlapping; peduncle 12.0–23.0(–30.0) × 0.2–0.4 cm, cylindric, green; peduncle bracts 4–6, 10.0–35.0 × 3.0–5.0 mm, ovate, apex acute to acuminate, green; rachis 5.0–14.0 × 0.7–1.0 cm, green. Flower bracts 3.7–4.4 × 1.2–1.6 mm, lanceolate to ovate, green, apex acuminate to acute; flower erect, white, dorsal sepal revolute, 1.7–2.2 × 1.0– 1.1 mm, ovate to triangular, white with purplish-brown spot at the apex, apex acute; lateral sepals patent, 2.6–3.3 × 1.2–1.4 mm, ovate, white with purplish brown spot at the apex, apex acute; petals revolute, 1.6–2.0 × 0.5–0.6 mm, linear, white, apex obtuse to acute; lip 1.7–2.4 × 2.0– 2.3 mm, white, inner surface pubescent. Column 1.0– 1.1 mm long, glabrous.

Distribution:— Restricted to Brazil: Rio de Janeiro, São Paulo, Paraná, Santa Catarina and Rio Grande do Sul ( Fig. 16 ).

Selected Specimens Examined:— BRAZIL. Paraná: Guaratuba, Praia do Mendanha , 24 September 1967, Hatschbach 17205 ( MBM) . Rio de Janeiro: Cabo Frio, road between Araruama Lagoon and the main road Cabo Frio- Arraial do Cabo , 16 August 1953, Restinga 865 ( K, R) . Rio Grande do Sul: Itacolomi , 14 August 1976, Waechter s.n. ( ICN 32452) . Santa Catarina: s.d., Brongniart s.n. (isolectotype ( P00366650 !); s.l., s.d., Brongniart s.n. (lectotype ( P00366650 !). São Paulo: São Paulo, Parque do Estado, 26 October 1961, Brolio 18 ( SP).

Habitat:— Prescottia densiflora occurs in humid, though well-drained soils in bright, open areas.

Conservation Status:— Not endangered.

Etymology:— Probably a reference to the many flowered inflorescence.

Notes:— Prescottia densiflora is characterized by elliptic, sessile to pseudopetiolate leaves, and an internally pubescent lip. Morphologically, P. densiflora is similar to P. oligantha , with which Wiggins & Porter (1971) considered it a synonym. Prescottia densiflora can be distinguished from it by its sessile to pseudopetiolate leaves and congested inflorescence with overlapping flowers. Phylogenetically, it is closely related to the other species with whitish flowers and an internally pubescent lip ( P. lancifolia , P. oligantha and P. ostenii ); however, P. densiflora is more closely related to P. lancifolia and P. ostenii than P. oligantha ( Azevedo 2009) .

IPNI indicates 1841 as the year of the new combination for Decaisnea densiflora , but number 34 of the Annals and Magazine of Natural History was published in 1840 ( Lindley 1840b). Moreover, The genera and species of orchidaceous plants ( Lindley 1840a), published in September 1840, cited P. densiflora as published in Lindley (1840b).

There were two syntypes for Decaisnea densiflora , one at P and another at K-L, both annotated with the same information as in the protologue. When Lindley (1840b) transferred D. densiflora to Prescottia , he said that Brongniart gave him a specimen. The specimen given to Lindley has the original illustration and for this reason was designated as lectotype of D. densiflora by Azevedo & van den Berg (2007a).

Figures

FIGURE 15. Prescottia densiflora. Drawn from fresh material. A. Habit. B,C. Flower. B. Dorsal view. C. Front view. D. Floral bract. E. Perianth parts, clockwise from top: lip, dorsal sepal, petal, lateral sepal. F,G. Column with pollinarium in place. F. Dorsal view. G. Ventral view. H. Pollinarium. (van den Berg 1417).

FIGURE 16. Distribution of Prescottia densiflora.