March, igoo. Plant.*; Utowan/e Millspaugh. 27 



if present, about one-half as long as the second, i-nerved; second 

 glume broadly ovate, obtuse, truncate, about two-thirds as long as 

 the spikelet, 5-nerved; third glume obtuse, nearly as long as the 

 flowering fruiting glume and with a palea nearly as long as itself, 

 5-nerved, palea distinctly 2-nerved and scabrous on the keels; flower- 

 ing glume acute, pedicels of the burs short and densely pubescent. 



This species is allied to Cenchrus echinatus, but the burs are 

 larger and the bristles more numerous and much longer. 



Pajaros Island. Alacran Shoals (1759)- Type in Field Col. Mus. 

 Herb. no. 61759. One plant only found, though being in full fruit 

 others may appear from seed. This plant grew in the very center of 

 the island where the booby nests are the thickest, and was the only 

 representative of the species on the shoals. 



The species was also found on the sandy east shore of Cozu- 

 mel Island, about four miles from the northeast point; rare (1607). 



Cenchrus tribuloides Linn, Sp. PI. 1050. 



On sand dunes at Santurce, Porto Rico (289). Under Coco 

 trees on north shore of Cayman Brae (1162), where it is called, as in 

 the United States, "Sand-bur." Shores of Grand Cayman, north of 

 Georgetown (1249), and southwest point of Perez Island, Alacran 

 Shoal (1756). 



Cenchrus viridis, Spr. Syst. 1: 301. 



Fields south shore of Culebras Island (619). Sand) 7 fields near 

 Spot Bay, Grand Cayman (1268). East shore of Cozumel Island 

 (1599), and arid plains south of Progreso, Yucatan (1682). A specimen 

 gathered along the roadway near Guanica village (808) is doubtfully 

 placed here. 



Stenotaphrum dimidiatum Brong. Dep. Voy. Coc. Bot. 127. 



S. Americanum Schrk. On a small juniper-covered islet in Ham- 

 ilton Bay, Bermuda (15). Waste grounds near the sea at Cape Cori- 

 entes, Cuba (1459). 



Sporobolus Domingensis (Trin.) Kunth. Enura. 1: 214. 



Vilfa Domingensis Trin. Arid scrub-land south of Progreso, 

 Yucatan (1713). 



.Sporobolus Indicus (Linn) R. Br. Prodr. r: 170. 



Agrostis Indica Linn. Roadside banks at Walsingham, Bermuda 

 (88), and near Port Antonio, Jamaica (936). 



Sporobolus Virginicus (L.) Kth. Rev. Gr. 1: 67. 



Agrostis Virginica Linn. Covering the south end of Perez 

 Island (1750), Pajaros Island, and a small patch on the west end of 

 Allison and Chica Islands, Alacran Shoal. 



Chloris barbata (L) Nash. Bull. Torr. Bot. Club. 25: 443. 



Andropogon barbatus Linn, non C. barbata. Southwest shore of 

 the bay at Charlotte Amalia, St. Thomas (410, 441); south shore of v 

 Culebras Island (573, 592); rare in cane fields near Guanica, Porto 

 Rico (735); and on the dry hillside of Morro Castle, Santiago de 

 Cuba (1064). 



