M. cm Viu Moe 
PRA. S rur 
66 Rhodora | [APRIL 
resemblance to L. Mildeana (Gottsche) Schiffn., but the gemmiparous 
branches and the gemmae themselves would indicate that it was really 
much more closely related to L. incisa (Schrad.) Dumort. Stephani, 
in fact, goes so far as to include it among the synonyms of L. incisa. 
Interesting observations on L. grandiretis have been published by 
Schiffner,! while a full account of the species, with figures, is given 
by K. Müller? : 
The stems of L. grandiretis are simple or sparingly branched and 
are more or less pigmented with purple or blackish brown on the lower 
surface. ‘The leaves are delicate in texture and pale green and are 
remarkable for being broader than long. In normal cases they are 
unequally bifid for about one third their length with broadly triangu- _ 
lar, bluntly pointed lobes, the margins of which are commonly entire. 
Toward the apex of the stem trifid leaves are often developed. The 
leaf-cells are unusually large and are accountable for the specific name 
of the plant. At the apices of the lobes, according to K. Miiller, the 
cells measure 40-50 u in diameter, but in the middle of the leaf they 
attain a length of 60-80 u and a width of 40-50 u. The walls are 
rather thick and small trigones are usually developed. "The cuticle 
is smooth. Underleaves are absent except in the female inflorescence. 
The gemmiparous branches bear the gemmae on the tips of crowded 
leaves, somewhat reduced in size, and the development of the gemmae 
quickly brings the growth of the branches to an end. The gemmae, 
which have recently been figured by Warnstorf,? measure 25-30 uin 
diameter. They are unicellular-or bicellular and are sharply angular 
or even stellate. 
Even in the absence of inflorescences L. grandiretis may usually be 
distinguished without much trouble from L. incisa. In the latter 
species the stems are green throughout, the leaves are longer than 
broad, the lobes of the leaves often bear angular-or spine-like teeth, 
the cells measure only 25 u in diameter at the apices of the lobes and 
only 30-40 u in the middle of the leaf, the cell-walls are thin, and tri- 
gones are scarcely to be demonstrated. The gemmiparous branches 
and the gemmae are much alike in the two species, although the gem- 
mae in L. incisa are distinctly smaller, averaging only 15 u in diameter. 
In the opinion of Warnstorf L. grandiretis is closely related to L. 
! Oesterr. Bot. Zeitschr. 57: [5]. 1907. 
? Rabenhorst's Kryptogamen-Flora 6: 705. f.322. 1910. 
? Hedwigia 63: 209. f.4. 1913. 
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