Your help is appreciated.    We depend on donations to help keep this site free and up to date for you. Can you please help us?

Orchidaceae

See list of 21 genera in this family
  • 1a. Labellum deeply concave to saccate (at least in the basal portion), forming a small to 
very evident pouch [Fig. 164]
    • 2a. Labellum saccate in only the basal portion, 1.8–12 mm long; inflorescence a spike or raceme, with 5–72 flowers [Fig. 166]
      • 3a. Principal leaves all basal, usually white-striped or white-reticulated [Fig. 165]; labellum white to white-green
      • 3b. Principal leaves borne on the stem, alternate, without white markings; labellum purple to purple-brown with pink near the apex or dark red
    • 2b. Labellum saccate ± throughout, 10–67 mm long; inflorescence a solitary flower or a spike-like raceme with 2 or 3 (–4) flowers
      • 4a. Labellum with 2 apical horns and a prominent fringe of yellow bristles; plants with 
1 leaf; flowers with 1 fertile anther; stem arising from a corm
      • 4b. Labellum without a pair of apical horns, lacking evident yellow bristles [Figs. 163,164]; plants with 2 or more leaves; flowers with 2 fertile anthers; stem arising from a short to elongate rhizome
  • 1b. Labellum neither inflated nor saccate, not forming a pouch [Figs. 167,171,174]
    • 5a. Labellum basally prolonged into a hollow spur (the spur short and saccate in Coeloglossum) [Figs. 173,175]
      • 6a. Flowers bilaterally asymmetrical (i.e., appearing lopsided); leaf single, abaxially purple, produced in autumn, withering by early spring, therefore, the flowering 
plants without well-formed leaves
      • 6b. Flowers bilaterally symmetrical; leaves 2 or more, less commonly single, abaxially green, produced in spring and present during flowering
        • 7a. Labellum white with magenta spots, 3-lobed, the middle lobe notched at the apex; leaf single, basal
        • 7b. Labellum not spotted, variously shaped but never 3-lobed with a notched middle lobe; leaves 1–several, basal or arranged on a stem
          • 8a. Stems conspicuously angled; labellum unlobed, typically white and strongly contrasting in color from the pink-magenta sepals and lateral petals (rarely 
all the perianth of similar color); viscidia enclosed in a single, 2-lobed bursicle
          • 8b. Stems terete; labellum unlobed, lobed, or fringed, ± similar in color to the remainder of the perianth (those Platanthera with 2 basal leaves usually have the sepals more strongly tinged with green than the petals); viscidia free, not enclosed in a bursicle
    • 5b. Labellum lacking a spur (flowers with a small, inconspicuous, adnate spur in Corallorhiza formed by the 2 lateral sepals) [Figs. 167,170,177]
      • 12a. Flowers not resupinate, the labellum the uppermost petal; labellum with a conspicuous brush of yellow-tipped hairs; leaves articulated, this appearing as a 
thin, transverse line near the base of the leaf
      • 12b. Flowers resupinate, the labellum the lowest petal; labellum with or without hairs 
or ornamentation of some type; leaves not articulated
        • 13a. Leaves whorled at the summit of the stem
        • 13b. Leaves or scales alternate or opposite, borne at base of plant and/or distributed along the stem
          • 14a. Flowers subtended by foliaceous, ovate bracts [Fig. 179]; labellum ornamented with 3 parallel, green, papillose ridges [Fig. 179]
          • 14b. Flowers subtended by rather inconspicuous, usually scale-like bracts; labellum ornamented or not, never with 3 parallel, green ridges
            • 15a. Flowers large, the labellum (12–) 17–35 mm long; flowers usually solitary
              • 16a. Leaves flat, numbering 1–3 on the stem, present at anthesis, the largest 7–25 (–32) mm wide; sepals and lateral petals distinct, the outer spreading
              • 16b. Leaves obscurely plicate, solitary on the stem, not fully formed at anthesis, 2–4 (–12) mm wide; sepals and lateral petals connate at the base, the outer erect
            • 15b. Flowers smaller, the labellum 1.3–12 mm long; flowers 3–180 per inflorescence
              • 17a. Principal leaves arranged in a single, opposite pair on the stem; labellum 2-lobed due to a conspicuous apical notch [Figs. 170,171]
              • 17b. Principal leaves 1–several, borne at base of plant and/or distributed along the stem; labellum entire or 3-lobed, without a single apical notch (with a prominent notch in Malaxis, but then with a small lobe at the base 
of the central notch) [Figs. 169,176]
                • 18a. Flowers predominantly white or cream (except for a yellow or green central area on the labellum in some species), sometimes tinged with yellow or green; leaves and stem bracts above them numbering 5 or more; labellum with a pair of basal callosities
                • 18b. Flowers not predominantly white or cream, variously colored and/or spotted; leaves and stem bracts (when present), numbering 4 or fewer; labellum without a pair of basal callosities
                  • 19a. Plants leafless at flowering time, with sheathing bracts only, arising from coral-like rhizomes; plants without chlorophyll, the stems brown to purple, or yellow-green in one species
                  • 19b. Plants with leaves at flowering time ( Aplectrum sometimes leafless at flowering, but the withered remnant usually present at stem base), arising from corms; plants chlorophyllous, the leaves and stems ± green at anthesis
                    • 20a. Leaf solitary, evidently plicate, produced at distal end of corm in late season and persistent through the winter, usually withering by flowering; labellum white with magenta spots (rarely all white-yellow); capsules pendent
                    • 20b. Leaf solitary or paired, not or only obscurely plicate, produced in spring, present during flowering, withering before winter; labellum green to yellow-green or brown-purple to pale purple, without spots; capsules spreading to erect
                      • 21a. Plants with 2 leaves, in a pair near the base of the stem; labellum 4–12 mm long; capsules 9–13 mm long
                      • 21b. Plants with a single leaf (rarely 2 and then not paired), 
borne on the stem; labellum 1.3–2.3 mm long; capsules mostly 5–8 mm long

Show All Couplets

 Show photos of:   Each photo represents one genus in this family.