70 



M. C. COOKE ON NETTLE STEMS AND THEIR MICRO- FUNGI. 



on the dead stems, thus limiting the period of observation to one 

 habitat, and one time of the year. This hmitation promises far 

 better resnlts than a more desultory method, and the experience so 

 gained will lead thereafter to a wider field, and more extended 

 researches. 



Fig. 1. 



To commence with one of the most 

 singular of the fungi found on old net- 

 tles, we will name Acrospermum compres- 

 sum, because it is also one of the largest, 

 and most prominent to the naked eye, 

 and the most distinct that we shall 

 have occasion to name (fig. 1). It has 

 the appearance of little black flattened 

 clubs, from one-and-a-half to two lines 

 high, opening at the apex, and dis- 



charging therefrom long thread-like spores. A number of these 

 clubs are usually found together, and their size renders them rather 

 conspicuous. The character of the spores, as well as the form of 

 the perithecia, is so distinct, that there can be no fear of confound- 

 ing this with any other fungus found in a similar locality. The 

 spores are not contained in asci, or the clubs might be supposed to 

 belong to the Sphceriacei, but hitherto no more perfect or complete 

 condition has been observed. It is just possible that a better 

 acquaintance may hereafter lead to the discovery of some condi- 

 tion in which asci are produced. 



Hitherto in one locality only we have found on very old and 

 decaying nettle stems a species of Dinemasporium^ which seems to 

 be specifically distinct from any previously described, although 

 included in the '' Handbook" as a variety of No. 1365. This is 

 not the place to enter upon the discussion of the limits of species 

 in general, nor the distinctions in this particular instance, but our 

 own opinion is strongly in favour of separating the form on nettle 

 stems from that found on grasses. It may be observed that this 

 fungus appears at first as rigid black bristles, bursting through the 

 cuticle in a short linear series ; soon afterwards, especially in moist 

 places, or during damp weather, in early spring, intense black, velvety 

 elevations, from one to two lines in length, burst through and ap- 

 pear on the surface. These assume an elongated cup-shape when 

 dilated, closed when dry, surrounded by stiff, erect black bristles. 

 The hymenium is the interior of the cup, in which is produced a 



