86 Rhodora [May 
FORMS OF OPHIOGLOSSUM VULGATUM IN EASTERN 
NORTH AMERICA. 
SIDNEY F. BLAKE. 
SEVERAL years ago during a month’s collecting in southern New 
Hampshire I discovered a rather large colony of Ophioglossum vul- 
gatum, from which when the spikes became ripe over four hundred 
specimens were collected. The plants, which grew in two adjacent 
bits of sphagnous meadowland, usually in the open but occasionally 
on the edges of thickets, show great variation in size, shape, and posi- 
tion of leaf, size of spike, and number of fronds, sufficient to consti- 
tute half a dozen “species” if brought back by collectors from as 
many regions. Usually there is but one frond on a rootstock, but 
not rarely two are present, either both fertile or one sterile, and equal 
or unequal in size. The presence of two fronds on a rootstock, which 
has been emphasized as a more or less distinctive mark of Ophioglossum 
arenarium (= O. vulgatum var. minus Moore), is shown by specimens 
in the Gray Herbarium to be of not infrequent occurrence practically 
throughout the American range of O. vulgatum, and is not correlated 
with any other characters either of size or leaf form. It apparently 
occurs rather more frequently in O. Engelmanni Prantl, but can 
hardly be considered of any importance in distinguishing species or 
varieties in this immediate group. 
'The ordinary leaf form in this series seems to be oblong, obtuse or 
rounded at tip, broadest about the middle and only slightly narrowed 
at the ends, with the base somewhat decurrent on the stem. An 
average specimen measures 5 by 1.5 cm., with extremes of 7 by 2 to 
3.8 by 1 cm. The sterile segment is situated almost always at or 
above the middle of the hypergean axis, but occasionally at a con- 
siderable distance below it, a feature upon which stress has also been 
laid in descriptions of O. arenarium, but which frequently occurs in 
some individuals of a colony of otherwise normal O. vulgatum. This 
common oblong leaf grades on the one hand into a form with shorter 
and broader ovate leaf, more conspicuously contracted at the base, 
and on the other connects with a larger form having oblong or ovate- 
oblong sterile segment as much as 96 mm. in length. Some broader- 
leaved intermediates lead to plants with oval leaf more than half as 
