306 ORCHID ACEAE (OKCHIS FAMILY) 



Artificial Key to Genera 



■i. Two fertile anthers ; lip an inflated sac 1. CTPEiPKmtTM. 



i. One fertile anther h. 

 b. Flowers with a distinct slender spnr (this at least 2 mm. long). 

 Leaves present at flowering time. 

 Caudicles of pollinia divergent, not contained in a special pouch or 



bursicule '6 Habenaria 



Caudicles of pollinia convergent, contained in a special pouch or 



bur.sicule 2. Orchis. 



Leaves absent at flowering time IT. Tipularia 



6. Flowers without a conspicuous spur, the lip sometimes saccate c. 

 c. Leaves one or more (in fspiranthefi, Arethusn, and Aplectrum some- 

 times absent or inconspicuous at flowering time); plant green d. 

 d. Perianth at least 15 mm. across ; sepals and petals more or less 

 spreading, not strongly recurved e. 

 4. Leaves linear to linear-lanceolate, grass-like, sheathing the scape 

 near the base. 

 Flowers several, resupinate, with one floral bract ... 5. Calopogon. 

 Flowers solitary, rarely 2, not resupinate, with 2 floral bracts, 



one posterior, the other anterior, subtending the ovary . 6. Arethusa. 

 e. Leaves elliptic-oblong, ovate, or cordate, sometimes whorled. 



Lip saccate, bearded 1£. Calypso. 



Lip not saccate, with a longitudinal more or less tuberculate 



crest or beard 4. Pogonia. 



Lip saccate, not bearded 7. Serapias. 



d. Perianth less than 15 mm. across ; sepals and petals connivent or 

 spreading. 

 Petals joined to the upper sepal but not coalescent with it. 

 Lip saccate at base, devoid of basal callosities ; leaves variegated 9. Epipaotis. 

 Lip not distinctly saccate, with a horn-like callosity within on 



each side at base ; leaves not variegated .... 8. Spiranthes. 

 Petals and sepals free. 

 Petals filiform or linear, less than 2 mm. broad. 



Leaf solitary 13. Miorostylib. 



Leaves 2, near the middle of the stem 10. Listeka. 



Leaves 2, basal ; li|) not pointed 14. Lipakis. 



Leaves basal ; lip pointed 12. Malaxis. 



Petals not filiform, at least 2 mm. broad 16. Aplectikim. 



C. Leaves wanting ; scaly saprophytes with yellowish or purplish stems. 



Lip with a callus on each .«ide of the mid-nerve at base . . . 11. Corali.oukhiza. 

 Lip with 5 or 6 longitudinal crests 18. Hexai.E( tris. 



1. CYPRIPEDIUM L. Lady's Slipper. Moccasin Flower 



Sepals spreading, all three distinct or in most cases two of them united into 

 one under the inflated sac-like lip. Petals mostly spreading, linear or oblong. 

 Column declined, on each side a fertile stamen with its short filament bearing 

 a 2-celled anther ; pollen loose and pulpy or powdery-granular, the face of the 

 anther converted into a viscid film ; on the upper side of the column a dilated 

 petaloid, but thickish staminode, or infertile stamen ; stigma terminal, obscurely 

 3-lobed, moist and roughish. — Roots coarsely fibrous. Leaves many-nerved and 

 plaited, sheathing at the base. Stems pubescent. Flowers solitary or few, 

 large and showy. -(Name incorrectly Latinized from Kt^Tr^ts, Venus^ and ir^5i\ov, 

 a shoe^ therefore by some authors .spelled Cypripedihnn.) 



§ 1. Tfie three sepals separate. 



\. C. arietinum R. Br. (Ram's Head L.) Stem slender, 15-30 cm. high; 

 leaves 3 or 4, elliptic-lanceolate, nearly glabrous ; upper sepal ovate-lanceolate, 

 acute, lower sepals and the petals linear, similar, madder-purple. L5-2 cm. long, 

 exceeding the whitish crimson-veined lip, wliich is silky pubescent within. 

 {Criosanthes borealis Haf. ; — Swamps and rich woods, rare and local, Que. 

 to Man., s. to Me., Mass., N. Y., and Minn. May, June. (China.) 



§ 2. The two lower sepals united. 



* Stem elongated, leafy to the top, \-^-flowered ; lip slipper-shaped, not fissured 



in front, hut with a rounded open orifice, 



•*- Sepals and linear twisted petals acute, longer than the lip. 



■»-f Lip yellow. 

 2. C. parviflorum Salisb. (S.mallkr Yki.low L.) Stem 10-00 cm. high; 

 petals and sepals greenish, much suffused with madder-purple, 3-5 cm. long; 



