THE RELATIONSHIP OF ASPLENIUM ANDREWSIL. 
By Wittram R. Maxon. 
In the final brochure ! of the Proceedings of the Biological Society 
of Washington for 1904, volume 17, Prof. Aven Nelson published, as 
one of several undescribed species collected in Colorado by Mr. D. M. 
Andrews, a supposed new Asplenium, which he dedicated to its 
discoverer as Aspleniuwm andrewsii.?, The description and notes are 
as follows: 
“Rootstock short, wholly enveloped in matted roots; stipes naked, ebeneous below, 
becoming green above, from 2-10 cm. long, somewhat angled or striate; lamina thinly 
herbaceous, deltoid-ovate or narrower, 3-10 cm, Jong, somewhat narrower at its widest 
part, bipinnatifid, diminishing nearly uniformly from base to tip; pinnz lanceolate, 
the lower nearly at right angles to the rachis, the upper ascending, gradually diminish- 
ing and passing into the pinnatifid tip, all rather closely approximate and subopposite 
or the lower more distant (1 cm. or more) and alternate; pinnules 3-12 mm. long, 
ovate, more or less cuneate at base, sharply incised but cut not quite to the costa, 
sharply and somewhat incisely serrate; the veins rather inconspicuous and but slig::tly 
divergent; sori short but nearly connecting to those in the successive lobes, so forming 
almost a continuous sorus from base to apex of pinnule; indusium straight, forced 
back and finally concealed by the sporangia. 
‘Perhaps most nearly allied to A. bradleyi D.C. Eaton, but probably not very closely 
even to this. Mr. Andrews writes of it as follows: ‘The most interesting item on the 
list to me. I am sending a better specimen. It is certainly indigenous and grows 
on the south face of a white sandstone (alkaline) cliff extending along Boulder Creek 
for a mile or more, the ferns growing in crevices abundantly for nearly the whole dis- 
tance. Itis growing with Cheilanthes feci, a specimen of which I send you. The sand- 
stone is porous and is not entirely dry.’” 
Not long after this Professor Underwood called my attention to the 
obviously close relationship of this form to the Old World Asplenvum 
adiantum-nigrum, and, if I am not mistaken, to the great difficulty 
or impossibility of distinguishing it specifically from that species, as 
usually accepted by European botanists. In 1906, however, the 
species was recognized by him as valid in Rydberg’s Flora of Colo- 
rado, and again in his article ‘‘American Ferns, VI—Species added 
to the flora of the United States from 1900 to 1905,”’* here with the 
comment, ‘This new discovery from Colorado is a member of the 
adiantum-nigrum group of Asplenium, and is closely related to Asple- 
1Tssued December 27, 1904. 
2 Page 174. 1 
