J.) I ANNALS OF THE MISSOURI BOTANICAL GARDEN 



the greater length of melanopoda and frequently the stronger 

 bulb development of the latter. The range in spore size is inter- 

 mediate, overlapping the larger of /. melanopoda and the smaller 

 of /. Butleri. 



Much of the material representing this form has been collected 

 in early spring. It is a question whether the fineness of leaves 

 is related to the early development, as the lack of pigment seems 

 to be. Certain it is that some stations have yielded only material 

 labeled "Butleri immaculata" in May, and only "melanopoda" 

 in June and July. Whether /. Butleri as found in Oklahoma (In- 

 dian Territory) by Butler, owed its characteristic size and fineness 

 to the alkali flats in which it developed, is another ecological 

 point worth determining. The series from /. melanopoda devel- 

 oping in moisture through so-called pallida, in drier surroundings, 

 to /. Butleri, conceivably might be related to the environment. 

 Pending further evidence in regard to relation, material showing 

 the characteristic habit of /. Butleri is placed with that species, 

 though most of it occurring outside of Oklahoma shows the com- 

 bination of characters which connect it quite definitely also with 

 /. melanopoda. 



39. I. Butleri Engelm. Bot. Gaz. 3: 1. 1878; Baker, Jour. 

 Bot. 18: 105. 1880; Motel. & Vendr. Actes Soc. Linn. Bord. 

 36: 360. 1883; Engelm. Trans. St. Louis Acad. Sci. 4: 388. 

 1882; A. A. Eaton in Gray, Manual, ed. 7, 61. 1908. 



/. Butleri var. immaculata Engelm. Trans. St. Louis Acad. 

 Sci. 4: 388. 1882. 



Calamaria Butleri Kuntze, Rev. Gen. PI. 2: 828. 1891-93. 



Corm 2-lobed; leaves 8-30, 8-15 cm. long, more slender and 

 rigid than /. melanopoda, tapering to apex; stomata numerous; 

 peripheral strands usually 4, sometimes more in number; ligule 

 elongated, cordate at base; sporangium oblong, 6-7 mm. long, 

 marked with brown lines; velum very narrow; megaspores vari- 

 able, commonly 1*0-650 u in diameter, sometimes only 360 m, 

 marked with numerous tubercles, usually distinct, occasionally 

 confluent; microspores 27-37 u long, papillose. ' 



Distribution: Tennessee, Missouri, Arkansas, Kansas, and 

 Oklahoma. 



Specimens examined: 



Tennessee : Cedar Glades, Lavergne, May, Gattinger (N. Y. Bot. 



