1917] St. John,— Remarks on North American Alopecurus 165 
the species represented as in their general grouping and the appearance 
of the area. The almost complete absence of shrubs, the dominance 
of grasses, and the level topography combine to, give it a strong 
resemblance to a hydrophytic prairie of northern Illinois. Indeed 
it may be assumed that this area represents a relic colony of prairie 
plants, persisting from a time when prairies occupied a wide extent 
in southern Michigan, and now somewhat mixed with various marsh 
species which have immigrated in recent times from the neighboring 
swamps and bogs. 
Paper no. 157 from the BOTANICAL LABORATORY 
OF THE UNIVERSITY OF MICHIGAN. 
REMARKS ON SEVERAL NORTH AMERICAN SPECIES OF 
ALOPECURUS. 
HAROLD St. JOHN. 
A THOROUGH study of abundant material and dissections of spike- 
lets from each specimen have made it clear to the writer that Alope- 
curus geniculatus L. and A. aristulatus Michx.' have constant characters 
and should be treated as distinct species: 
A. aristulatus Michx. is a native of northern Europe, Asia, and in 
America from the region of the Gulf of St. Lawrence south to Mary- 
land and west to. the Pacific slope. It has a short straight awn 
attached to the back of the lemma midway between its top and base. 
The awn is included in or slightly extruded beyond the glumes. 
Mature spikelets measure from 2-2.2 mm. in length. 
A. geniculatus L., a native of northern Eurasia, has a long exserted 
twisted awn attached near the base of the lemma, usually one quarter 
of the distance from its base to its summit. Mature spikelets of this 
species measure 3 mm. in length. The drawings in Britton & Brown’s 
1 A. fulvus Sm. Eng. Bot. xxi. 1, 467 (1805) is synonymous with A. aristulatus, and is often 
taken up for it on the basis of having been published in 1790, as the first volume of Smith’s 
English Botany was, but volume xxi in which the original description and plate appeared was 
published in 1805. A. aristulatus was published by Michaux in his Fl. Bor.-Am. i. 43 (1803). 
