Notes on Grasses 223 



NOTES ON GRASSES. 



Paul Weatherwax, Indiana University. 



In order better to understand the relationships of the maize plant 

 the writer has for several years carried on a taxonomic study of the 

 grasses as a group, this work necessitating a somewhat thorough ex- 

 amination of the floral structures of many species. In these studies 

 there have been observed a number of characteristics which might 

 significantly be included in descriptions or considered in studies of the 

 evolution and relationships of the grasses. The purpose of this and 

 succeeding papers is to place on record some of these peculiarities. 



1. The habitat of Paspalum repens Berg. — This plant is abundant 

 along the banks of Eel River at the northern edge of Greene County, 

 Indiana, this marking the most northern occurrence of the species that 

 has been reported for the State. The plants in this location differ from 

 most descriptions of the species in being distinctly terrestrial. This 

 locality has been under observation nearly every year since 1918, and 

 although conditions for growth of the plant in the water are ideal, not 

 a single specim.en has thus far been found in the water. They occur 

 rather in shady places, on rich, moist sandbars, five or six feet above 

 the ordinary level of the water at this season. The plants are more 

 erect than those seen elsewhere in the typical habitat, and the sheaths 

 are little or not at all inflated. 



2. Laminate lemmas in Phleiim praterise L. — On a hill near the 

 Indiana University waterworks reservoir, northeast of Bloomington, 

 Indiana, there have been observed in September and October for four 

 or five years, timothy plants whose inflorescences are more or less 

 rough and leafy in appearance. Examination of these shows that the 

 lemmas of many of the spikelets have well developed leaf blades and 

 ligules. The flowers of these spikelets seem to be normal, and partly 

 developed seeds have been found in a number of them. 



In the cases observed, several spikelets were missing from the lower 

 part of each abnormal inflorescence, the mutilation resembling the 

 work of grasshoppers. The presence of numerous bacteria in the 

 minute yellowish exudations from the scars left by the removal of these 

 spikelets, however, suggests the possibility of a diseased condition, 

 which might also account for the unusual development of the lemmas. 



Cases similar to this have been reported for other grasses. Britton 

 and Brown^ note that in arctic regions and in the mountains of New 

 England there is found the so-called variety vivipara of the species 

 Festuca ovina L., "with the scales wholly or partly transformed into 

 small leaves." Kerner and Oliver' mention several, chiefly arctic, "vivi- 

 parous" grasses, in which small plants develop in the spikelets. Col- 

 lins^ has reported a similar occurrence in maize. This anomaly in 

 timothy is probably an expression of the same tendency of floral struc- 



1 Illustrated Flora, 2(1 Ed., Vol. 1, p. 271, 1913. 



= Natural History of Plants, 2:818-820, 1895. 



3 Contributions from the National Herbarium, 12 :453-456, 1909. 



"Proc. Ind. Acad. Sci., vol. 33, 1923 (1924)." 



