98 American Midland Naturalist Monograph No. 2 



35. Burmanniaceae Blume — Burmannia Family 



1. Thismia Griff. 



T. americana N. E. Pfeiff. "Chicago, 111., in open prairie," N. E. Pjeiffer. 

 Known only from the original collection; type, herb. Field Mus.; isotype, herb. 

 Univ. of III. Discovered in Aug. 1912; now probably extinct. [^Sarco siphon 

 americanns Schlecht.j. 



36. Orchidaceae Lindl. — Orchid Family 



1 . Lip large, inflated, moccasin-shaped; leaves plaited; fertile anthers 2....1. C])pripedium 

 1 . Lip concave or flat, not moccasin-shaped; fertile anther 1. 

 2. Plants with ordinary green foliage at flowering time. 



3. Flowers distinctly spurred, the spur 2 mm. or more in length. 



4. Flowers bicolored, the lip white and the sepals and petals purple; leaves 2, 

 basal, oval 2. Orchis 



4. Flowers concolored 3. Habenana 



3. Flowers spurless. 



5. Flowers large (more than 1 cm. broad), solitary or few. 



6. Leaves grass-like; flowers several, racemose, pink-purple 4. Calopogon 



6. Leaves not grass-like. 



7. Flowers axillary; lip not crested 5. Tnphora 



7. Flowers terminal, solitary or few; lip fringed and crested 6. Pogonia 



5. Flowers smaller, several to many, in spikes or racemes. 



8. Flowers sessile or nearly so, spicate, white or greenish white. 



9. Spike more or less twisted spirally; leaves alternate, not variegated, often 

 soon withering 7. Spiranihes 



9. Spike not spiral; leaves basal, often whitish-variegated 8. Coodviera 



8. Flowers distinctly pedicelled, racemose, greenish or purplish. 



10. Leaf solitary near the middle of the stem, ovate or oval, clasping; 



flowers many, greenish, 2-3 mm. long 9. Malaxis 



10. Leaves two, basal; flowers few 10. Liparis 



2. Plants with leaves absent at least at flowering time (or with a single basal withered 

 one persisting). 



1 1 . Inflorescence a spirally twisted spike; flowers white or greenish white 



7. Spiranthes 



1 I . Inflorescence not spirally twisted. 



12. Stem bulbous at base, with one basal, oval green leaf usually withering by 



flowering time.. I 1 . Aplectrum 



12. Plant lacking chlorophyll; rhizomes coral-like; leaves reduced to scales 

 12. Corallorrhiza 



1. Cypripedium L. — Lady's Slipper 



L Sepals oval, not twisted, shorter than the white lip, which is 3-4 cm. long, 

 tinged with purple; wet woods or springy places, rare. Peoria Co., Brendel; 

 Lake Co., Gates. June-July. Showy Lady's Slipper. [C hirsutum sensu 

 auth., haud Mill.; C. spcctabile Salisb.} C. reginae Walt. 



L Sepals lanceolate, attenuate, twisted, equalling or exceeding the lip. 



2. Lip white, 2-2.5 cm. long, purple-veined inside; sepals and petals greenish 

 yellow, purple-lined; bogs, swamps, or wet ground on "original prairie," 

 very rare. May-June. White Lady's Slipper C. candidiim Muhl. 



2. Lip yellow, 2-5 cm. long; wooded hillsides or in ravines, or bogs, rare. 

 May-June. Yellow Lady's Slipper. [C. pubescens Willd.; C. hirsutum 



