ORCHID FA.MILY 



479 



7. IRIDIUM Salisb. Trans. Hort. Soc. London 1: 291. 1812. 

 Stems erect, leafy, from a cluster of tuberous roots. Flowers in a twisted spike white 

 spurless. Sepals and petals narrow, erect or more or less connivent ; lip oblong sessile or 

 nearly so. the base embracing the column, with a callous protuberance on each side, the dilated 

 summit spreadmg and usually entire. Column very short oblique, terminating' in a shct 

 terete spike. Stigma ovate, with an acuminate bifid beak, covering the anther and stigmatlc 

 only beneath. Anther without a lid, borne on the back of the column, erect. Pollinia two 

 one m each sac, powdery. Capsule ovoid or oblong erect. [The anther has a fancied 

 resemblance to the head of an ibis, hence the name.] 



About 55 species, widely distributed over temperate and tropical regions. Besides the following about a 

 dozen other species inhabit eastern North America. Type species, Ibidiiim spirale Salisb. 



Callosities at the base of the lip obsolete. I. I. romanzoffianum. 



Callosities at the base of the lip nipple-shaped, directed downward. 2. I. poriifolium. 



1. Ibidium romanzoffianum (Cham & Schl.) 



House. 



Hooded Ladies' Tresses. 



Fig-. 1171. 



Spiranthes romansoffiana Cham. & Schl. Linnaea 3: 32. 1828. 

 Gyrostachys romancoffiana McM. Met. Minn. 171. 1892. 

 Orcludstrum romancoffianum Greene, Man. Bay Region 306. 1894. 

 Gyrostachys stricta Rydb. Mem. N. Y. Bot. Card. 1: 299. 190l! 

 Ibidium romanzoffianum House, Muhlenbergia 1: 129. 1906. 

 Ibidium strictiim House, Bull. Torrey Club 32: 381. 1905. 



Stem glabrous, 15^5 cm. high. Lower leaves linear 

 to linear-lanceolate. 5-35 cm. long; spike 5-15 cm. long, 

 dense ; flowers white or greenish, 6-8 mm. long ; lip 

 oblong, contracted below the cusped dilated apex, tlie 

 callosities at base obsolete. 



Wet meadows, Upper Sonoran to Canadian Zones; Alaska to 

 New Foundland, south to southern California, Colorado, and 

 Pennsylvania, May-Sept. Type locality: Unalaska. 



2. Ibidium porrifolium ( Lindl.) 



Rydb. 



\\'estern Ladies' Tresses. Fig'. 1172. 



spiranthes porrifolia Lindl. Gen. & Sp. Orchid 



467. 1840. 

 Gvrostachvs porrifolia Kuntze, Rev. Gen. PI. 2: 



664. 1891. 

 Orchiastriim porrifolium Greene, Man. Bay 



Region 306. 1894. 

 Ibidium porrifolium Rydb. Bull. Torrey Club 32: 



610. 1905. 



Stem slender, 2-4 dm. high, glabrous. 



Leaves narrowly oblanceolate or linear, 



1-2 dm. long ; spike 5-10 cm. long, rather 



densely flowered ; flowers greenish white ; 



lip lanceolate, scarcely dilated at the apex; 



with 2 nipple-shaped callosities at the base. 



Bogs and marshes. Upper Sonoran and Tran- 

 sition Zones: Washington and Idaho to southern 

 California and Colorado. June-Aug. Type lo- 

 cality: northwest America. 



8. OPHRYS [Toui-n.] L. sp. PI. 945. 1753. 



Small perennial herbs with roostocks and fleshy-fibrous roots. Stem slender, bearing 1 or 2 

 sheathing scales towards the base, and 2 opposite leaves near the middle. Flowers in a 

 terminal racerne. spurless. Sepals and petals similar, spreading or reflexed, free. Anther 

 without a lid, jointed to the column. Pollinia 2, powdery, united to a minute gland. Capsule 

 ovoid or obovoid. [Greek, the eyebrow.] 



About a dozen species native of the north temperate and arctic regions. Besides the following two others 

 occur in eastern North America. Type species, Orphys oiata L. 



Lip broadly wedge-shaped, retuse or 2-lohed at apex. 



Lip 9 mm. long; ovary glandular. 1. Q. comallarioides. 



Lip 3 mm. long; ovary glabrous. 2. O. caurina. 



Lip oblong or linear, 2-cleft to near the middle. 3 Q cordata 



