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

780 ORCHIDACEAE/SPIRANTHES
3. Lip usually widest near apex, white or creamy green to green, usually marked or veined
with green (usually with distinctive diverging green lines); inflorescence tightly to loosely
spiraled to 1-sided; leaves usually present at flowering time; plants flowering Apr–Jun.
4. Perianth 5.5–8.5(–11) mm long, white, the lip usually with green veins near apex _________ S. praecox
4. Perianth 10–16.5 mm long, creamy green to green, the lip with darker green veins near
apex ____________________________________________________________________ S. sylvatica
2. Perianth 2.5–5 mm long; leaves (if present) 6–25 mm wide, spreading, the � short broad
blades with a distinct petiole, ovate to ovate-lanceolate.
5. Lip pure white; root 1(–2); perianth 2.5–3(–5) mm long, gaping from near middle; plant
flowering Jun–Sep ___________________________________________________________ S. tuberosa
5. Lip with a yellow to green center; roots several, in a fascicle; perianth 3–5 mm long, gaping
closer to apex (ca. 2/3 or 3/4 distance from base); plant flowering either Feb–May or Sep–
Nov.
6. Leaves usually not persisting until flowering time; plant usually flowering relatively later,
mostly Sep–Nov _____________________________________________________________ S. lacera
6. Leaves usually present at flowering time; plants flowering relatively earlier, mostly in
spring, Feb–May.
7. Lip white with green center; sepals and petals white with green basal portion; leaves
oblanceolate _____________________________________________________________ S. eatonii
7. Lip cream to yellowish white to yellowish green with yellow center; sepals and petals
cream to yellowish white or yellowish green, without green basal portion; leaves
ovate __________________________________________________________________ S. floridana
1. Axis of inflorescence pubescent (as seen under magnification—use 10X hand lens), the pubescence
blunt to capitate (= end enlarged) or pointed; leaves (if present at flowering time) cauline
and/or basal.
8. Inflorescence with flowers single-ranked (= inflorescence with a single discernable vertical
row or rank of flowers spiraling one to many times up the inflorescence, the inflorescence
sometimes scarcely coiled and thus secund or 1-sided).
9. Leaves absent at flowering time; plants flowering (late Aug–)Oct–Nov.
10. Lateral petals � obovate, distinctly narrowest at base; lip (when flattened) narrowest
in basal 1/3, oval, not constricted at middle, 5–7 mm long; in side view the sepals extending
further (appearing longer) than the petals; species endemic to a few counties
in the s part of the Post Oak Savannah and one in the Pineywoods ____________________ S. parksii
10. Lateral petals lanceolate, not distinctly narrowest at base; lip (when flattened) widest
basally, usually slightly to distinctly constricted near the middle and then slightly widened
at the apex, 6–12 mm long; in side view all perianth parts extending about the
same distance; species widespread throughout East TX _____________________________ S. cernua
9. Leaves present at flowering time (may be withered and dry); plants flowering Feb–Jul.
11. Leaves ovate, 2–6 cm long; upper surface of lip with a patch or tuft of pubescence;
plants flowering Feb–May ________________________________________________ S. brevilabris
11. Leaves linear-lanceolate to linear-oblanceolate, 5–35(–40) cm long; upper surface of
lip without a patch of pubescence; plants flowering Apr–Jul.
12. Lip usually widest near base, often fleshy-thickened, white with yellow or greenish
yellow center.
13. Pubescence of inflorescence pointed (use hand lens); tuberosities at base of
lip not incurved, not prominent, much less than one-fifth as long as lip; species
common and widespread in East TX _____________________________________ S. vernalis
13. Pubescence of inflorescence capitate; tuberosities at base of lip distinctly
incurved, prominent, ca. one-fifth as long as lip; species rare in East TX, known
only from the Pineywoods ___________________________________________ S. laciniata