Flora of the Southeastern United States
2022 Edition

Colors

Data mode

Key to terrestrial orchids: Key to Orchidaceae

1 Leaves absent at flowering, or with a solitary leaf with a purplish undersurface withering at about the time of flowering.
..2 Flowers with a spur.
....3 Spur shortly obtuse, lip partially tubular; [s. FL]
....3 Spur long and slender, lip not partially tubular; widespread in our region, south in FL to ne. FL]
..2 Flowers without a spur.
......4 Flowers white, the lip, sepals, and petals all predominantly white.
........5 Lip white with a single central green stripe; leaves often fugacious
........5 Lip white, centrally yellow to greenish-white, occasionally with multiple green veins (as in S. praecox and S. sylvatica); leaves present, absent, or withering (fugacious) at flowering
......4 Flowers pink, greenish, yellowish, or purplish, the lip sometimes white or marked with white, the sepals and petals colored.
..........6 Lip strongly bearded.
............7 Flower solitary; [Mountains of SC, NC, and VA northwards]
............7 Flowers not solitary (inflorescence a raceme); [Coastal Plain of SC southwards]
..........6 Lip not bearded.
..............8 Lip with 2 fleshy keels near the base; pollinia 4; plants holomycotrophic (without chlorophyll) and never with leaves
..............8 Lip with 3-7 keels near the base or extending most of the length of the lip; pollinia 4 or 8; plants either holomycotrophic (without chlorophyll) and never with leaves, or with a plicate winter leaf withering shortly before flowering.
................9 Plants with a plicate winter leaf withering shortly before flowering (the withered remnant usually detectable); veins of the petals and sepals not strikingly different in color than the intervein areas; lip with 3 ridges; pollinia 4
................9 Plants never with leaves, holomycotrophic (without chlorophyll); veins of the petals and sepals strikingly different in color than the intervein areas; lip with 5-7 ridges; pollinia 8
1 Leaves present at flowering (Cleistesiopsis with a foliaceous bract at the summit of the stem).
..................10 Plants with evident, above-ground pseudobulbs, sometimes enclosed by sheaths.
....................11 Leaf bases tightly sheathing the stems, often petiolate.
......................12 Lip broadest near its apex; inflorescence typically a spicate raceme (prematurely umbellate in M. spicata); leaves to 10 cm long
......................12 Lip broadest near its apex; inflorescence typically a more open or lax raceme; leaves to 30 cm long.
........................13 Leaves 3-7, membranaceous, plicate; anthers green
........................13 Leaves 2, thickish, conduplicate; anthers yellow
....................11 Leaf bases not conspicuously clasping the stems (or if clasping, loosely so).
..........................14 Flowers predominantly yellow, pseudobulbs > 8 (-100) cm long.
............................15 Flowers without brown spots; pseudobulbs typically 10-30 (-100) cm long
............................15 Flowers with brown spots; pseudobulbs typically 8-15 cm long
..........................14 Flowers not predominantly yellow, pseudobulbs < 8 cm long.
..............................16 Leaves not plicate, with conspicuous dark green mottling
..............................16 Leaves plicate, without conspicuous dark green mottling.
................................17 Lip conspicuously bearded (or if not bearded, conspicuously keeled and with brownish-maroon veins extending to margins of lip)
................................17 Lip not conspicuously bearded.
..................................18 Perianth brown (white on lower surface); lip tubular
..................................18 Perianth pink or purple; lip not tubular.
....................................19 Lip with 5-7 conspicuous yellow-white keels
....................................19 Lip without 5-7 conspicuous yellow-white keels
..................10 Plants without above-ground pseudobulbs (either absent or subterranean).
......................................20 Leaf solitary.
........................................21 Leaf basal.
..........................................22 Flower with a spur.
............................................23 Leaf long petiolate, lanceolate-elliptic; lateral sepals conspicuously spreading with long acuminate apices; [s. FL]
............................................23 Leaf not long petiolate, orbicular; lateral sepals reflexed or slightly spreading without long acuminate apices, rather, typically blunt or rounded; [widespread; NC and TN northward]
..........................................22 Flower without a spur.
..............................................24 Flower solitary
..............................................24 Flowers in a raceme or spike.
................................................25 Flowers relatively large, primarily pink, purple, or white; flowers arranged in loosely arranged racemes
..................................................26 Lip below (resupinate); flowers white, often cleistogamous; lip white with purple margins, with keels
..................................................26 Lip above (not resupinate); flowers purple or pink (rarely white), chasmagomous; lip with yellow fringes (beard)
................................................25 Flowers relatively small, whitish; flowers arranged in densely (and sometimes also spirally) arranged spikes.
....................................................27 Dorsal sepal connivent with petals forming hood over columnn; lip sagittate-auriculate
....................................................27 Dorsal sepals not forming connivent hood with petals, or if rarely so, then lip pandurate (as in S. romanzoffianum)
........................................21 Leaf cauline.
......................................................28 Flowers in spikes or racemes, 5-many, reddish, yellowish, or greenish.
......................................................28 Flower solitary (-4), pink (rarely nearly white); [subfamily Vanilloideae; tribe Pogonieae].
........................................................29 Sepals brown to purple, linear or narrowly oblanceolate, 3-6.5 cm long, about 5 mm wide; leaf coriaceous
........................................................29 Sepals pink (rarely white), elliptic or oblanceolate, 1.3-2.7 cm long, 3-11 mm wide; leaf herbaceous
......................................20 Leaves 2-many.
..........................................................30 Lip inflated, pouch-like or slipper-like, 2-6 cm long
..........................................................30 Lip not inflated, or if so, then 0.3-1.1 cm long.
............................................................31 Leaves cauline.
..............................................................32 Leaves plicate; lip saccate or arcuate
................................................................33 Lip arcuate, with purple-brown marginal speckles; leaf sheaths inflated-tubular
................................................................33 Lip saccate, without purple-brown marginal spots; leaf sheaths tight and not inflated-tubular.
..................................................................34 Leaves typically many (3-14); 4-20 cm long; lip variously colored without conspicuous yellow disc; [widespread]
..................................................................34 Leaves typically fewer (2-5); 4-4.5 cm long; lip primarily white with conspicuous yellow disc; [s. FL]
..............................................................32 Leaves smooth, often creased at the midrib, but not plicate; lip not saccate.
....................................................................35 Leaves whorled, terminating the stem; [subfamily Vanilloideae; tribe Pogonieae]
....................................................................35 Leaves alternate or opposite, not terminating the stem.
......................................................................36 Leaves 2, opposite, near the middle of the stem
......................................................................36 Leaves (2-) 3-many, alternate, variously distributed on the stem.
........................................................................37 Plant with aerial roots throughout stem; lip orange-red, deeply 3 to 4 lobed and marginally fimbriate; [subfamily Epidendroideae]
........................................................................37 Plant without aerial roots throughout stem; lip variously colored, if orange then not deeply 3 to 4 lobed.
..........................................................................38 Lip without a spur; leaves 0.8-8.0 cm long.
............................................................................39 Distal portion of lip not uniformly yellow; leaves ovate, 0.4-2.0 cm long
............................................................................39 Distal portion of lip uniformly yellow; leaves linear or narrowly lanceolate, 1-8 cm long
..........................................................................38 Lip with a spur; leaves linear, lanceolate, or narrowly elliptic, 5-40 cm long (at least the larger > 5 cm long, except in Aspidogyne, with lanceolate to ovate leaves 1.5-6.5 cm long).
..............................................................................40 Leaves 1.5-6.5 cm long, with inflated tubular sheaths; plants from creeping rhizomes
..............................................................................40 Leaves 5-40 cm long, sessile; plants from fleshy or fusiform roots.
................................................................................41 Lip divided into 3 linear divisions, the divisions not further divided, fringed, or eroded
................................................................................41 Lip not divided into 3 divisions, or divided into 3 divisions but the divisions not linear.
..................................................................................42 Spur saccate, 2-3 mm long, the orifice minute
..................................................................................42 Spur elongate and slender, 4-50 mm long, the orifice larger
............................................................31 Leaves basal (sometimes with bladeless sheaths upward on the stem).
....................................................................................43 Leaves plicate.
......................................................................................44 Lip oriented upward (not resupinate); flowers pink to white
......................................................................................44 Lip oriented downward (resupinate); flowers greenish, purplish-brown, maroon or yellowish.
........................................................................................45 Sepals ascending or apically reflexed, not converging
........................................................................................45 Sepals converging, not ascending or reflexed
....................................................................................43 Leaves smooth, often creased at the midrib, but not plicate.
..........................................................................................46 Lip with a spur.
............................................................................................47 Leaves long petiolate, not basally sheating stems; sepals longer (to 30 mm), narrowly lanceolate
............................................................................................47 Leaves not long petiolate, basally sheating stems; sepals shorter, variously shaped
..............................................................................................48 Flowers bicolored, the lip white, the sepals and petals pink; leaves 2
..............................................................................................48 Flowers not bicolored, the lip, petals, and sepals similarly colored; leaves 2-5
................................................................................................49 Lip deeply divided into 3 linear segments; leaves 3-5
................................................................................................49 Lip entire; leaves 2
..........................................................................................46 Lip without a spur.
..................................................................................................50 Leaf blade or leaves ascending.
....................................................................................................51 Inflorescence a raceme; lip with pink-purple coloration along margin; flowers larger, not tightly spiraling
....................................................................................................51 Inflorescence a spike; lip without pink/purple coloration along margin; flowers smaller, often spiraling or tightly assembled
..................................................................................................50 Leaf blades more-or-less horizontally oriented, flat against the ground or 1-2 cm above it.
......................................................................................................52 Flowers orange-red (except rarely light green as in S. lanceolata forma albidaviridis)
......................................................................................................52 Flowers never strongly orange-red, instead white, yellowish, greenish, or brown (including coppery).
........................................................................................................53 Lip oriented upward (flowers not resupinate).
..........................................................................................................54 Lip with green spots
..........................................................................................................54 Lip without green spots (sometimes with green coloration but not green-spotted).
............................................................................................................55 Large flowers distinctly pedicellate on racemes; lip short-caudate, 4.5-7 mm long; petals obliquely triangular
............................................................................................................55 Minute flowers sessile on spikes; lip apiculate, 1-2 mm long; petals narrowly obovate
........................................................................................................53 Lip oriented downward (flowers resupinate).
..............................................................................................................56 Leaves with prominent white or pale green variegation on midrib and/or veins; [subtribe Goodyerinae]
..............................................................................................................56 Leaves without prominent variegation; [subtribe Spiranthinae].
................................................................................................................57 Flowers brown or copper colored
................................................................................................................57 Flowers white or green colored.
..................................................................................................................58 Lip and perianth segments each with a single central green stripe; leaves more or less fugacious
..................................................................................................................58 Lip and perianth without a central green stripe; occasionally with multiple green veins on the lip; leaf often persistent.
....................................................................................................................59 Flowers white, often also marked or veined with yellow or green; [widespread in our region]
....................................................................................................................59 Flowers green, greenish-yellow, or bronze; [FL southwards]
......................................................................................................................60 Lip canaliculate (grooved longitudinally), without conspicuous yellow throat; flowers greenish-brown or coppery
......................................................................................................................60 Lip not grooved longitudinally, with conspicuous yellow throat; flowers greenish-white