keys to the vascular plants of east texas - Botanical Research ...

756 ORCHIDACEAE
white, greenish white, green, yellow-green, yellow, or orange, without any pinkish, reddish,
or purplish pigmentation.
7. Leaves short-petiolate, 3–8, spirally arranged, the sheaths inflated; spur saccate, ca. 2.5–
3.5 mm long; species extremely rare or absent from East TX (not seen there since 1924)
________________________________________________________________________ Platythelys
7. Leaves not petiolate, 1–several, alternate, the sheaths not inflated, basally sheathing the
stem; spur slender cylindrical to club-shaped, 4–140 mm long; including species widespread
and common in East TX.
8. Lip 3-parted at least halfway to base.
9. Lip parted into 3 � linear divisions, the divisions entire or nearly so ______________ Habenaria
9. Lip parted into three divisions, the divisions themselves variously divided into
thread-like segments __________________________________________________ Platanthera
8. Lip not 3-parted, entire to lobed to conspicuously fringed ______________________ Platanthera
6. Flowers without a spur; flower color either white, ivory, cream, or green, sometimes with
green or yellow markings OR if not so then variously colored with at least some pinkish to
reddish or purplish pigmentation (but not orange).
10. Leaves not cauline, in a basal rosette.
11. Flowers resupinate (thus lip the lowermost of the petals), white to ivory, cream, or
green, with or without green or yellow markings on the lip; inflorescence a spike;
leaves present and green, or withered and brown, or absent ____________________ Spiranthes
11. Flowers NOT resupinate (thus lip the uppermost of the petals), greenish white,
without green or yellow markings on the lip; inflorescence a raceme; leaves present
at flowering time, green, not withered ______________________________________ Ponthieva
10. Leaves cauline or if basal, then not in a rosette.
12. Flowers not resupinate (thus lip the uppermost of the petals), pink to rose-pink,
rose-purple, or rarely white; leaves 1(–3), basal, not cauline; column arcuate, persistent
in fruit ___________________________________________________________ Calopogon
12. Flowers resupinate (thus lip the lowermost of the petals), variously colored; leaves
1–several, cauline, not basal; column various, if arcuate, not obviously persistent in
fruit.
13. Flowers white with the entire lip bright yellow; introduced species expected
in such habitats as flower beds, lawns, and gardens; species currently documented
in TX only from Brazos and Harris cos. ______________________________ Zeuxine
13. Flowers variously colored but not as above; native species in various natural
habitats; including species widespread in East TX.
14. Leaves 1(–2).
15. Inflorescence with 10–50(–160) flowers; petals green; lip minute, 1.1–
2.3 mm long; base of stem swollen into a pseudobulb __________________ Malaxis
15. Inflorescence with 1(–3) flowers; petals pink to rose or white; lip 12–
33(–38.5) mm long; base of stem not swollen into a pseudobulb.
16. Sepals pink to rose or white; lip (12–)15–25 mm long, heavily
bearded with a white-yellow beard; petals apices not recurved;
species widespread in Pineywoods and Post Oak Savannah _________ Pogonia
16. Sepals olive-green, brown, or maroon; lip 21–33(–38.5) mm long,
not bearded (but with a central yellowish crest); petals with recurved
apices; species extremely rare or absent from East TX (not
seen there since before middle of 20th century) ___________________ Cleistes
14. Leaves 2–several.
17. Leaves opposite or subopposite or whorled, at apex of stem (at base
of inflorescence).
18. Leaves 2, opposite or subopposite; inflorescence a raceme of