Polystachya concreta (Jacq.) Garay & H.R.Sweet

George R. Proctor (2012). Flora of the Cayman Isands (Second Edition). Royal Botanic Gardens, Kew

Morphology General Habit

Caespitose epiphytes, lithophytes or terrestrial herbs

Morphology Stem

Stems pseudobulbous to slightly swollen at base, hidden by leaf-sheaths, composed of several subequal intenodes, 1–4 cm long

Morphology Leaves

Leaves 2–4, sheathing at base; blades conduplicate and petiole-like at base, thin, narrowly oblong to elliptic, mostly acute, 3.5–21 cm long

Morphology Reproductive morphology Inflorescences

Inflorescences erect, generally paniculate but racemose in small plants; peduncle compressed, covered by scarious sheaths, 12–17 cm long; branches of panicles secund, rachises many-flowered, 12–24 cm long

Morphology Reproductive morphology Flowers

Flowers yellow or pale green with a white lip, non-resupinate; dorsal sepal ovate- elliptic, acute, 2.5–4 mm long, lateral sepals triangular, 4.5–5.0 mm in its longest dimension, attached to the column foot to form a mentum; petals narrowly oblanceolate, acute-obtuse, 2–3 mm long; lip trilobed, attached to the column foot, cuneate, rhombic, 3–5 mm long, 3 mm wide, lateral lobes falcate, apices almost reaching the apex of the midlobe, midlobe quadrate to oblong, retuse, subapiculate, disc with a linear, densely farinose callus (pseudopollen), 2 mm long, ending at the base of the midlobe.

Morphology Reproductive morphology Flowers Column

Column short, cylindrical, 1.5 mm long, column foot 2–3 mm long

Morphology Reproductive morphology Fruits

Capsules brown at maturity, ellipsoid, 6–12 mm long.

Distribution

Little Cayman. Pantropical(?). African and Asian synonyms may represent different species even though some of them have been used for neotropical plants (e.g. Polystachya flavescens).

Recognition

Like Polystachya foliosa, morphological variation in vegetative parts of P. concreta is substantial with quite small plants producing inflorescences, and sometimes populations consist of only such small plants. However, floral morphology is relatively invariant. Over the centuries, there have been a number of attempts to recognize segregate taxa from both of these species, which may make sense locally but do not appear to hold up across the range of the species.

Extinction risk predictions for the world's flowering plants to support their conservation (2024). Bachman, S.P., Brown, M.J.M., Leão, T.C.C., Lughadha, E.N., Walker, B.E. https://nph.onlinelibrary.wiley.com/doi/full/10.1111/nph.19592

Conservation

Predicted extinction risk: not threatened. Confidence: confident

Distribution

Biogeografic region: Andean, Pacific. Elevation range: 0–1600 m a.s.l. Native to Colombia. Colombian departments: Cauca, Chocó, Magdalena.

Habit

Herb, Epiphyte.

Conservation

Listed in Appendix II of CITES.

Ecology

Habitat according IUCN Habitats Classification: forest and woodland, shrubland, native grassland, artificial - terrestrial.

Orchidaceae, I. la Croix & P.J. Cribb. Flora Zambesiaca 11:2. 1998

Morphology General Habit

Robust epiphytic herb, sometimes lithophytic.

Vegetative Multiplication Pseudobulbs

Pseudobulbs sometimes obscure, 0.5–5 cm long, up to 1 cm wide at the base, conical, ribbed, 3–5-leaved.

Morphology Leaves

Leaves 15–30 × 1.5–5.5 cm, oblanceolate or elliptic, slightly 2-lobed at the apex, dark green, sometimes purple-tinged.

Morphology Reproductive morphology Inflorescences

Inflorescence (floral axis) 18–45 cm long, with up to about 9 secund branches; branches 1–5 cm long, densely many-flowered. Peduncle covered with scarious sheaths; rhachis slightly pubescent, with papery acute sheaths.

Morphology Reproductive morphology Flowers

Flowers very sparsely pubescent on the outside, usually bright yellow with a paler lip, but sometimes green or pink with a white lip; the lip occasionally has a purple-tipped mid-lobe.

Morphology Reproductive morphology Flowers Pedicel and Ovary

Pedicel and ovary c. 6 mm long.

Morphology Reproductive morphology Inflorescences Bracts

Bracts 2–4 mm long, linear-lanceolate, acuminate.

Morphology Reproductive morphology Flowers Calyx

Dorsal sepal 3–4.3 × 1.8–2.5 mm, ovate, apiculate; lateral sepals 5–7 × 3–4 mm, obliquely ovate, apiculate; mentum rounded, c. 3.5 mm high.

Morphology Reproductive morphology Flowers Corolla

Petals 2–3.5 × 1 mm, spathulate.

Morphology Reproductive morphology Flowers Labellum

Lip 3.5–5 × 2.5–4 mm, 3-lobed in apical half; disk covered with mealy hairs; callus obscure, a longitudinal, fleshy ridge 1.7–2 mm long; mid-lobe recurved, 1.5–2.5 × 2.5–3 mm, ± orbicular, emarginate, undulate on the margins, tessellate when dry; side lobes oblong or triangular-falcate, acute.

Morphology Reproductive morphology Flowers Column

Column c. 1.5 mm long.

Orchidaceae, V. S. Summerhayes. Flora of West Tropical Africa 3:1. 1968

Morphology Reproductive morphology Flowers

Flowers greenish to pale yellow with orange to purple markings.

Orchidaceae, V. S. Summerhayes. Flora of Tropical East Africa. 1968

Morphology General Habit

An epiphytic plant (9–)20–62 cm. long.

Morphology Stem

Stems pseudobulbous at base, to 15 cm. long, 0.7 cm. wide, 3–5-leaved; pseudobulbs ovoid, 0.6–1.3 cm. long, 0.5–0.8 cm. diameter.

Morphology Leaves

Leaves suberect, somewhat distichous, oblanceolate, elliptic or oblong-elliptic, minutely unequally bilobed at apex, obtuse or rounded, 13–30 cm. long, 1.3–5.7 cm. wide.

Morphology Reproductive morphology Inflorescences

Inflorescence much longer than the leaves, paniculate, 18–47 cm. long; peduncle terete, covered with scarious imbricating sheaths; rhachis more or less covered with papery acute sheaths, sparsely pubescent; branches secund, distant, 1–5 cm. long, densely many-flowered; bracts linear-lanceolate, acuminate, 2–4 mm. long.

Morphology Reproductive morphology Flowers

Flowers sparsely pubescent on outer surface, very variable in colour, creamy yellow, pale green, pink or dull red, lip white with a pink mid-lobe.

Morphology Reproductive morphology Flowers Calyx

Dorsal sepal oblong-elliptic, acute, 3–4.3 mm. long, 1.8–2.3 mm. wide; lateral sepals obliquely ovate, apiculate, 3–5.6 mm. long, 2.8–3.6 mm. wide, forming with the column-foot a conical mentum to 3.4 mm. high.

Morphology Reproductive morphology Flowers Corolla

Petals ligulate to spathulate, apiculate, 2–3.6 mm. long, 0.6–1.1 mm. wide.

Morphology Reproductive morphology Flowers Labellum

Lip clawed, 3-lobed at or above the middle, 3.5–5.2 mm. long, 2.5–4 mm. wide; side lobes falcately oblong, subacute or obtuse, 1.2 mm. long; mid-lobe suborbicular, emarginate, tessellated when dry, margins crenulate-undulate, 1.6–2.5 mm. long, 2–2.2 mm. wide; callus a fleshy ridge 1.7 mm. long, tapering towards the base and rounded at the apex.

Morphology Reproductive morphology Flowers Column

Column 1–1.6 mm. long.

Habitat

In rain-forest; 0–1650 m.

Distribution

K5 K7 T3 T4 T6 T7 T8 U2 U4 Z Sierra Leone to Ethiopia and south to Angola, Mozambique and Zimbabwe