Disa P.J.Bergius

Orchidaceae, I. la Croix & P.J. Cribb. Flora Zambesiaca 11:1. 1995

Morphology General Habit

Terrestrial herb with perennating tubers.

Vegetative Multiplication Tubers

Tubers testicular, rarely absent.

Morphology General

Sterile shoots produced occasionally, to 15 cm long with several basal sheaths and several erect conduplicate acute leaves to 40 cm long. Fertile shoots to 100 cm tall.

Morphology Leaves

Leaves radical, basal or cauline, linear to ovate, soft to rigid, lax to imbricate, monomorphic to dimorphic, green at flowering time, occasionally hysteranthous, conduplicate to flat, grading into the floral bracts or sharply distinct from the floral bracts.

Morphology Reproductive morphology Inflorescences

Inflorescence racemose with one to numerous flowers.

Morphology Reproductive morphology Flowers

Flowers not resupinate, resupinate or doubly resupinate, 4–80 mm in diameter, usually red or white, rarely blue or yellow or green.

Morphology Reproductive morphology Inflorescences Bracts

Bracts usually green, ovate, acute or acuminate, rarely dry and brown.

Morphology Reproductive morphology Flowers Calyx

Lateral sepals lanceolate to broadly ovate, rounded to acuminate, often keeled, patent, sometimes ascending or descending. Dorsal sepal erect, galeate, rarely cucullate or dish-shaped, usually ovate, rarely oblong or spathulate, with a spur which is obsolete to 8 cm long, slender or rarely massive, rarely flattened or with a dorsal or ventral groove, horizontal, descending or ascending.

Morphology Reproductive morphology Flowers Corolla

Petals lanceolate to square, erect or reflexed, acute or truncate, the apex curving over the anther or over the rostellum, or curved out of the galea, often with a complex plane shape.

Morphology Reproductive morphology Flowers Labellum

Lip usually lanceolate, rarely spathulate or broadly ovate, occasionally linear.

Morphology Reproductive morphology Flowers Column

Rostellum 3-lobed; lateral lobes erect, square or horn-like, flat or canaliculate, free or fused to the petals by a long keel; central lobe usually small, fleshy, rarely tall.

Morphology Reproductive morphology Flowers Androecium Stamens Anthers

Anther 2-celled, horizontal, ascending or pendent; viscidia usually separate, borne on the lateral rostellum arms.

Morphology Reproductive morphology Flowers Gynoecium Stigma

Stigma pedicellate or sessile, the surface flat, concave or convex, tripulvinate with the rear cushion often smaller than the lateral cushions.

Orchidaceae, I. la Croix & P.J. Cribb. Flora Zambesiaca 11:1. 1995

Morphology General Habit

Terrestrial herb, perennating by tubers.

Vegetative Multiplication Tubers

Tubers testicular.

Morphology Leaves Leaf sheaths

Basal sheaths hyaline, obtuse.

Morphology Leaves

Leaves cauline, usually imbricate; leaf bases sheathing; blades usually erect, elliptic to linear-lanceolate, the lowermost the largest, the upper grading into the floral bracts.

Morphology Reproductive morphology Inflorescences

Floral bracts often overtopping the flowers, ovate to lanceolate, acute to acuminate. Inflorescence dense to lax, cylindric to secund.

Morphology Reproductive morphology Flowers

Flowers resupinate, purplish, brown or green.

Morphology Reproductive morphology Flowers Calyx

Dorsal sepal shallowly galeate, 2.5–15 mm long, usually oblong, obtuse, usually with a spur pendent from the base of the galea; spur slender or clavate, obsolete to longer than the galea. Lateral sepals patent or reflexed, often shorter than the galea, usually oblong.

Morphology Reproductive morphology Flowers Corolla

Petals obliquely narrowly ovate-oblong, acute to bifid; the broad base enclosing the anther; the apex erect within the galea, or partially exserted from the galea.

Morphology Reproductive morphology Flowers Labellum

Lip patent to pendent, linear to elliptic, subfleshy.

Morphology Reproductive morphology Flowers Androecium Stamens Anthers

Anther horizontal to semi-pendent with a single large concrete viscidium and 2 cells.

Morphology Reproductive morphology Flowers Column

Rostellum simple with a deep notch containing the viscidium and with 2 often well developed lateral flanges flanking the anterior part of the anther.

Morphology Reproductive morphology Flowers Gynoecium Stigma

Stigma equally or unequally tripulvinate, shortly stipitate to as tall as the rostellum.

Morphology Reproductive morphology Flowers Gynoecium Ovary

Ovary usually twisted, 5–25 mm long.

Orchidaceae, I. la Croix & P.J. Cribb. Flora Zambesiaca 11:1. 1995

Morphology Reproductive morphology Flowers Androecium Stamens Anthers

Anther horizontal or ± pendent, 2-celled with cells parallel; viscidia 2, separate or fused.

Morphology Reproductive morphology Flowers Column

Rostellum erect, lanceolate, acute, equally 3-lobed, rarely with the lateral lobes canaliculate and the central lobe absent.

Morphology Reproductive morphology Flowers Gynoecium Stigma

Stigma horizontal, shortly pedicellate, the odd lobe smaller than the lateral lobes.

Morphology Reproductive morphology Flowers Gynoecium Ovary

Ovary patent to ± spreading, 1–1.3 cm long.

Morphology General Habit

Terrestrial herb perennating by tubers.

Vegetative Multiplication Tubers

Tubers testicular, 1–6 cm long.

Morphology Stem

Stem erect, grasslike, 10–100 cm tall, base usually sheathed in old leaf fibres.

Morphology Leaves

Basal leaves 5–20, linear, flat or rolled, subsclerophyllous, produced during, before or after flowering; cauline leaves brown, scattered or imbricate on the stem, acuminate.

Morphology Reproductive morphology Inflorescences

Inflorescence lax, 1–30-flowered.

Morphology Reproductive morphology Inflorescences Bracts

Bracts dry, usually not as long as the flowers, ± broadly ovate, acuminate to setaceous.

Morphology Reproductive morphology Flowers

Flowers resupinate, usually blue or shades of blue, to white with pale blue veins, rarely purplish-red with green parts.

Morphology Reproductive morphology Flowers Perianth

Spur borne horizontally from the base of the galea, at length straight, decurved or curved upwards, rarely longer than the sepals, cylindrical or conical.

Morphology Reproductive morphology Flowers Calyx

Lateral sepals usually patent, 6–30 mm long, lanceolate to ovate, obtuse to acute. Dorsal sepal erect to angled forwards, generally galeate, rounded to acuminate, usually ovate in front view.

Morphology Reproductive morphology Flowers Corolla

Petals with a basal anticous lobe; lobe oblong-ovate, flanking the stigma; petal limb lower part linear or lorate, reflexed and flanking the anther; petal limb upper part lanceolate to expanded fan-like or more or less bifid, gently to abruptly curving upwards behind or near the apex of the anther.

Morphology Reproductive morphology Flowers Labellum

Lip ± dissected, rarely entire, usually ovate in outline, rarely spathulate, always specialized in some way.