Jennings: A New Species of Ibiuium. 4Sr) 



by House, " Further Notes on the Orchids of Central New York ", '' 

 have quite materially changed our conce[)tion of several of the species 

 and their synonymy. The writer would adopt, for reasons of prior 

 definite publication as stated by House, ^ the genus H>iiiiuin of Salis- 

 bury (1812) rather than the questionable Gyrosfathis (1S07) of 

 Persoon or the Spiranthes fiSiS) of L. C. Richard, and the species 

 here referred to are accordingly placed under that heading. 



Key to thk Speciks ok Iiuhuim Occurring ix the NoRruKAsrERN 

 United States. 



Flowers 3-ranked ; steins not twisted, or but slightly so. 

 Sepals and petals more or less connivent into a hood. 



/. striitutn (Kydberg) House.'' 

 Lateral sepals separate, free. 



.Spike 2-8 cm. long ; callosities minute or none. 



Lip less than 5.5 mm. long, constricted at or above the middle. 



/. paiviflontin (Chapman). 

 Lip more than 5.5 mm. long, not conspicuously constricted. 



I. plantiis;ineiiin (Rafinesque) House. 

 Spike 8-15 cm. long; callosities conspicuous. 

 Spike 12-14 mm. thick ; callosities .'-traight. 



Flowers yellowish ; spike acute ; lower bracts longer than flowers. 



/. ochroleiicuni (Rydberg) House.' 

 Flowers white; spike obtuse ; lower bracts shorter than flowers. 

 /. ceniuHiit (Linnaeus) House. 

 Spike 16-25 mm. thick ; callosities incurved. 



Flowers white ; callosities pubescent ; lateral petals obtuse. 



/. inciirvitin. 

 Flowers yellowish ; callosities glabrous; lateral petals acute. 

 /. odoratiiin (Nuttall). 

 Flowers alternate ; spike secund by twisting of the stem. 

 Stem leafy, lower bracts elongated, persistent. 



Outer sepals lanceolate ; lip oblong, outer end broadest, smooth beneath. 



/. prcccox (Walter). 

 Outer sepals linear ; lip ovate to ovate- oblong, broadest below, pubescent 

 beneath. /. tv;-;/<?/« (Engelmann & Oray) House. ^ 



Stem a scaly scape ; leaves basal, fugacious. 



Root usually a single tuber; spike about 2.5 cm. long. 



/. Beckii (Lindley)." 



3 House, FL D., "Further Notes on the Orchids of Central New York," Bull. 

 Torr. Bot. Club, 32: 373-382, 1905. 

 ♦ Ames, /. c, includes this with Spiraiil/ies Ronianzoffiana Chamisso. 

 5 Ames, /. c, regards this as " An upland form " of SpirantJies ariiua Richard. 

 "> {Gyrostachys linearis Rydberg) as in Britten's Manual, 300, 1905. 

 ' (^Gyrostachys Grayi (Ames) Britten) as in Britten's Manual, 300, 1505- 



