Click the number at the start of a key lead to highlight both that lead and its corresponding lead. Click again to show only the two highlighted leads. Click a third time to return to the full key with the selected leads still highlighted.

Click images to enlarge and show more photo credit.

Key to terrestrial orchids: Key to Orchidaceae

Orchidaceae

Copy permalink to share | Check for keys that lead to this key

1 Leaves absent at flowering, or with a solitary leaf with a purplish undersurface withering at about the time of flowering.
(c) Ware, Richard & Teresa - CC-BY-NC, permission granted to NCBG
  2 Flowers with a spur.
(c) Ware, Richard & Teresa - CC-BY-NC, permission granted to NCBG
    3 Spur long and slender, lip not partially tubular nor bearded; widespread in our region, south in FL to ne. FL]
    3 Spur shortly obtuse or short-conic (usually somewhat rounded at the tip), lip partially tubular or conspicuously bearded
      4 Lip bearded, with evident fringed keels; [non-native of variously disturbed or cultivated habitats, occasionally occurring in pine rocklands]
      4 Lip not bearded, lacking keels entirely (sometimes with magenta coloring but these not raised); [native of rockland hammocks in s. FL]
(c) Ware, Richard & Teresa - CC-BY-NC, permission granted to NCBG
(c) Cressler, Alan M.
  2 Flowers without a spur (the lip sometimes saccate but not extending further below as would a spur).
        5 Flowers white, the lip, sepals, and petals all predominantly white.
          6 Lip white with a single central green stripe; leaves often fugacious
          6 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
        5 Flowers pink, greenish, yellowish, or purplish, the lip sometimes white or marked with white, the sepals and petals colored.
(c) Cressler, Alan M.
             7 Lip strongly bearded.
(c) Brinker, Samuel - CC-BY-NC, permission granted to NCBG
               8 Flower solitary; [Mountains of SC, NC, and VA northwards]
(c) Ward, Scott G
               8 Flowers not solitary (inflorescence a raceme); [Coastal Plain of SC southwards]
(c) Cressler, Alan M.
             7 Lip not bearded.
                 9 Lip with 2 fleshy keels near the base; pollinia 4; plants holomycotrophic (without chlorophyll) and never with leaves
                 9 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.
                   10 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
                   10 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).
(c) Montes de Oca, Joseph - CC-BY-NC, permission granted to NCBG
(c) Matt - CC-BY-NC, permission granted to NCBG
(c) Montes de Oca, Joseph - CC-BY-NC, permission granted to NCBG
                     11 Plants with evident, above-ground pseudobulbs, sometimes enclosed by sheaths (these sometimes partially apparent in Malaxis, if so the leaves usually tightly clasping the stems).
(c) Cressler, Alan M.
                       12 Leaf bases tightly sheathing the stems, often petiolate.
(c) Cressler, Alan M.
(c) acjci - CC-BY-SA
                          13 Lip broadest near its base (proximal); flowers resupinate (for those species in our flora area; excluding M. spicata) inflorescence typically a spicate raceme (sometimes prematurely appearing apically umbellate in M. unifolia); leaves to 10 cm long
(c) Ward, Scott G
(c) Cressler, Alan M.
                          13 Lip broadest near its apex (distal); inflorescence typically a more open or lax raceme; leaves to 30 cm long.
(c) Riella, Fabrício Mil Homens - CC-BY
                            14 Leaves 3-7, membranaceous, plicate; anthers green
                       12 Leaf bases not conspicuously clasping the stems (or if clasping, loosely so).
                              15 Flowers predominantly yellow, pseudobulbs > 8 (-100) cm long.
(c) Hammer, Roger L.
(c) Hammer, Roger L.
                                16 Flowers without brown spots; pseudobulbs typically 10-30 (-100) cm long
(c) Hammer, Roger L.
                                16 Flowers with brown spots; pseudobulbs typically 8-15 cm long
                              15 Flowers not predominantly yellow, pseudobulbs < 8 cm long.
(c) Campos, Aidan
                                  17 Leaves not plicate, with conspicuous dark green mottling
(c) Matt - CC-BY-NC, permission granted to NCBG
                                  17 Leaves plicate, without conspicuous dark green mottling.
(c) Cressler, Alan M.
                                    18 Lip conspicuously bearded or bearing bumpy projections
(c) Matt - CC-BY-NC, permission granted to NCBG
                                       19 Perianth primarily brown or green (white on the backs of the sepals and petals OR the lip greenish-white with brown lateral venation); lip tubular (Phaius) or not (Eulophia).
(c) Cressler, Alan M.
                                           21 Lip with 5-7 conspicuous yellow or white keels, the keels sometimes distally undulate.
                                             22 Inflorescence arising basally (directly from the pseudobulb and on separate stems from the leaf culms)
                     11 Plants without above-ground pseudobulbs (either absent or subterranean).
(c) Cressler, Alan M.
© Floyd A. Griffith
                                                      26 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]
                                                          28 Flowers relatively large, primarily pink, purple, or white; flowers arranged in loosely arranged racemes
(c) Griffith, Floyd A.
                                                            29 Lip above (not resupinate); flowers purple or pink (rarely white), chasmogomous; lip with yellow fringes (beard)
                                                          28 Flowers relatively small, whitish; flowers arranged in densely (and sometimes also spirally) arranged spikes.
                                                                 31 Flower solitary (-4), pink (rarely nearly white); [subfamily Vanilloideae; tribe Pogonieae].
                                                                                      41 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).
(c) Hammer, Roger L.