RIIAPIITDOSTEGIUAt CCESPITOSUM 85 



gatherings, are exactly identical with the j)lants ah'eady discussed. 

 The species is, in fact, a practically cosmopolitan one throughout the 

 tropical and subtroj^ical regions of the Southern hemisphere, extending 

 also into the temperate zone. 



This point, however, having been reached, a much more perplexing 

 one is to fix the limits of the species. In its jmore normal forms it is 

 recognized at once by its robust habit and comparatively wide, and 

 widel}^ pointed — often, indeed, obtuse — leaves, very concave, with the 

 margin usually more or less widely reliexed, especially where the leaf 

 contracts to the apex ; the erect, shortly and widely pointed entire or 

 subentire perichietial bracts, the seta ranging round 1 cm. in length, 

 but generally a little over, and the short, often turgid, capsule, with 

 a more or less distinct neck, and usually suberect and only slightly 

 asymmetrical, but often distinctly curved and sometimes horizontal 

 or almost nodding. The areolation is often one of the most marked 

 characters, the cells being rather short, with a linear-elliptic lumen, 

 which in the broadly-pointed leaves often becomes much wider and 

 shorter at apex, often quite widely and shortly elliptic, but is in most 

 eases rendered more or less obscure and opaque by the cell contents 

 or primordial utricle : the efcect being a greyish appearance quite 

 different from that of many species of Rhaphidostegium, where it is 

 frequently chlorophyllous, elongate, and pellucid. This rather marked 

 character, however, of areolation occurs in some other species which 

 can hardly be included here, and its presence can therefore scarcely be 

 taken as certainly indicating R. coespitosum ; while quite a number 

 of forms which I cannot separate from that species show a very 

 narrow and not conspicuously opaque areolation. Broadlj^ speaking, 

 the short wide type of cell is associated with a wide and widely 

 pointed, even obtuse leaf, while the narrower and more acuminate 

 forms show the narrow and less opaque cells. 



It may reasonably be asked how a species supposed to embrace 

 such extremes of leaf form is to be defined, and the difficult}^ must be 

 admitted. At the same time, after examining many scores of speci- 

 mens from all parts, I have only found one direction in which I have • 

 experienced an}^ difficulty in defining the limits of the species. The 

 perichajtial bracts in lihapliidostegimn appear to me, as also in the 

 allied genus Sematophyllicm^ to afford one of the most effective 

 specific characters, and in R, coespitosum these leaves, erect, not 

 greatly differing in size but usually narrower than the stem and 

 branch leaves, with rather broadly tapering, not very finely acuminate 

 ])oints, entire or nearly so, are fairly constant tlii-oughout the range 

 of plants which I refer to R. coespitosum. Add to this the short and 

 turgid capsule, with a short but usuall}^ distinct neck, erect or slightly 

 inclined, and usually slightly curved or asymmetric, not pendulous 

 and very rarely horizontal, on a seta varying from •7-l'5 cm. in 

 length, and one has a combination of fruiting characters not found, 

 I think, in any other species with at all the vegetative characters of 

 R. coespitosum. The difficulty that does occasionally arise is with 

 the smaller and more slender forms, where both leaves and perichsetial 

 bracts tend to be narrower and more finely^ acuminate, with longer 

 and more pellucid cells, usually correlated with a smaller capsule and 



