50 



ORCHIDACEAE 



Sisyrinchium — Blue-eyed Grass 



(Gr. sisyrinchion, a bulbous iris) 

 PI. 21, fig. D : 1, 2 • 



1. Leaves 2-6 mm. wide; stem prominently winged; spathe and bract 



glabrous \. angustifdlium 



2. Leaves .5-2 mm. wide; stem narrowly winged; spatbc and bract 



scabrous or puberulent S. campestre 



Orchidales Orchid Order 



Orchidaceae — Orchid Family 

 Perennial herbs, with bulbs, corms or tuberous roots, leaves sheathing sometimes reduced to 

 scales ; flowers irregular, with one of the petals more or less modified into a lip-like structure, often 

 with n spur below the lip, ovules minute and numerous; sepals 3 (or 2 by fusion), petals 3, sta- 

 mens 1 or 2, ovary 1-celled ; flower syncarpous, apopetalous, epigynous. irregular. 



I. Lip slipper-like, stamens 2 Cypripedium 



II. Lip not slipper-like, stamen 1 



1. Leaves of current season absent or concealed at time of flowering 



a. Rootstock coral-like; plant entirely leafless Corallorhica 



b. Plants with corms ; leaves present in late summer or autumn 



(1) Flowers numerous, small; leaf appearing in autumn Aplectrum 



(2) Flower solitary, large; leaf appearing at close of flowering 



season Arethusa 



2. Leaves conspicuously present at time of flowering 



a. Flowers showy, pink and white 



(1) Flower solitary; lip sack-shaped Calypso 



(2) Flowers in a raceme, lip flat 



(a) Sepals and lateral petals spreading, the latter thread-like Liparis 



(b) Sepals and lateral petals convergent, lanceolate Orchis 



b. Flowers greenish, lip flat Habcnaria 



Plate 22 : A, Cypripedium hirsutum ; B, Corallorrhiza trifida, inflorescence, flower, root- 

 stock ; C, Aplectrum hiemale, inflorescence, flower, plant in winter condition ; D, Arethusa 

 bulbosa ; E, Calypso bulbosa ; F, Liparis liliifolia; G, Orchis spectabilis ; H, Habenaria 

 bracteata. 



Cypripedium — Ladies' Slipper, Moccasin Flower 



(Gr. Cypris, Venus, pedion, slipper) 

 PL 22. fig. A 



1. All three sepals separate C.arietinum 



2. Lateral sepals grown together, forming a single structure behind the lip 



a. Plant with two basal leaves; plant with one flower C.acaule 



b. Plants with stems leafy to the top 



(1) Lip pink and white, large, as long as the sepals C. hirsutum(C.regi)iac) 



(2) Lip yellow or white, shorter than the sepals 



(a) Lip yellow 



x. Lip 1.3-3 cm. long, sepals purple-brown C. pan if lorn m 



\. Lip 3-5 em. long, sepals brownish yellow C. pari'iflorum pubescens 



(C. hirsutum) 



(b) Lip white C. cdndidum 



