1922] 



PFEIFFER — MONOGRAPH OF THE ISOETACEAE 149 



38. I. melanopoda Gay & Dur. Bull. Soc. Bot. Fr. 11: 102. 



1864; Engeim. Bot. Gaz. 3: 1. 1878; Baker, Jour. Bot. 18: 105. 

 1880, and Fern Allies, 128. 1887 ; Motel. & Vendr. Actes Soc. Linn. 

 Bord. 36: 372. pi. 14. fig. 1-3. 1883; A. A. Eaton in Gray, 

 Manual, ed. 7, 61. 1908. 

 /. melanopoda var. pallida Engeim. Trans. St. Louis Acad. Sci. 



4: 387. 1882. 



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



Corm 2-lobed; leavea 15-60, 15-40 cm. long, slender, erect, 

 firm, bright green, usually black and shining at base, with usu- 

 ally pale membranaceous border, little (2-3 cm.) extended above 

 sporangium level; stomata present; peripheral strands 4 or 6 

 cardinal, plus as many as 14 accessory groups; ligule subulate tri- 

 angular; sporangia oblong, 0.5-3 cm. long, marked by numerous 

 brown spots; velum variable, from very narrow to covering 1/2 

 of sporangium; megaspores 280-440 p in diameter, marked with 

 low tubercles, frequently confluent into short low wrinkles; mi- 

 crospores frequently ashy-gray, 20-30 p long, fine spinulose. 



Distribution: Illinois, Missouri, Iowa, Oklahoma, and Texas. 



Specimens examined: 

 Illinois: Ringwood, 1863, Vasey (Mo. Bot. Gard. Herb, and Gray 



Herb.); wet meadows, without date, Hall (Gray Herb.); 

 shallow border of pond, near Wady Petra, Stark Co., 30 

 June, 1898, Chase 86 (Mo. Bot. Gard. Herb.); drying bed 

 of shallow pond near Wady Petra, 26 July, 1898, Chase 136 

 (Mo. Bot. Gard. Herb.) ; Athens, Menard Co., Hall (Gray 

 Herb.); Athens, 1861, Hall (Gray Herb.); Athens, Septem- 

 ber, 1861, Hall (U. S. Nat. Herb.) ; ponds, Athens, Menard 

 Co., July, 1863, Dement (Mo. Bot. Gard. Herb.); from 

 small pond, in water, 6 inches deep, Athens, Menard Co., 3 

 June, 1865, Hall (Mo. Bot. Gard. Herb.); pond dry for 

 several days, Athens, 13 Jure, 1865, Hall (Gray Herb.) ; 

 Athens, 27 June*, 1865, Hall (Mo. Bot. Gard. Herb, and Gray 

 Herb.) ; "wet prairies, shallow ponds, now dry, in spring 

 under water," 19 June, 1865, Athens, Hall (Mo. Bot. Gard. 

 Herb, and U. S. Nat. Herb.) ; Athens, 30 October, 1865, Hall 

 (Mo. Bot. Gard. Herb.); Athens, second crop, in water, 3 

 November, 1865, Hall (Gray Herb.) ; Athens, 25 November, 

 1865, Hall (Mo. Bot. Gard. Herb.) ; "second crop," Athens, 

 18 November, 1865, Hall (Mo. Bot. Gard. Herb.) : Athens. 1 



