108(3 büllktiiN DK l'heriuër BOISSIER (2 me SKR.). 1905 (2) 



glabrous or bas dense intricate wool proceeding froro it, wbicb may or 

 may not conceal the whole periantb. Finally other species of Ptüotus 

 bave long dense straigbt articulate bairs, like tbose of Tricbinium, but 

 proceeding frorn the base or the lower half only. In the last named 

 group Ptüotus passes into Tricbinium as is exemplified by Ptüotus 

 Carlsoni, which is allied to Ptüotus grandißorus and yet bears a rela- 

 tionship to Trichiniüm Manglesbi. The upwards extensively glabrous 

 sepals, which the latter possesses are, however, exceptional aniong 

 Trichiniwns: 



The présence of teeth on the staminal cup of man y species of Ptüotus 

 is a character tili now unrecognised in that genus. They are most 

 clearly seen in Ptüotus psüotrichoides in diverging pairs between the 

 filaments, as fi'rst observed by Mueller in spécimens examined in the 

 field (see Psilotrichum capitatum, F. v. M. Frag. 1, 238 (1858). But in 

 a subséquent description of the plant (see Ptüotus psüotrichoides, 1. c. 

 XI, 97 (1878), Mueller iguored their existence. It may here be mentioned 

 that this Ptüotus is peculiar in having the lower leaves opposite, the 

 upper ones only being alternate. P. latifolius bas teeth of the same 

 description but not so diverging. P. Carlsoni, P. corymbosus and 

 P. spicatus bave a single small tooth between each pair of filaments. In 

 these five species the teeth are a constant character. In Ptüotus humilis 

 articulate bairs on the cup between the filaments are substituted for 

 teeth as is frequently the case in Trichiniüm. 



It should be explained that the filaments of Ptüotus are united at 

 the base into a cup. The angles between the filaments may be acute 

 (P. conicus, P. grandißorus and P. vülosißorus), in which case there is 

 a conséquent absence of teeth. Where there is a broad sinus between 

 the filaments, the teeth may be présent as in P. psüotrichoides and 

 P. latifolius, or they may be absent as in P. gomphrenoides, P. Roodi, 

 P. Murrayi, P. petiolatus and P. roseo-albus. 



In Trichiniüm the existence of teeth or ratber scales bas already 

 been recorded in the following species — T. calosiacJiyum, T. Drum- 

 mondii, T. Fraseri, T. Schwartzii and T. procerum. I bave also observed 

 their présence in T. beckerianum, T. helipteroides and T. démenti. 

 These instrastaminal scales are transparent and fringed in the eight 

 species mentioned, varying a little in shape in différent species and 

 measuring approximately one millimètre in lengtb and half a milli- 

 mètre in breadth. The différence between these scales and the single 

 minute tooth or pair of teetli of Ptüotus is perbaps worth noting, 

 although, as a sectional character, this, or even the présence or absence 

 of teeth, is valueless as it brings together species totally dissimilar in 

 other respects. 



Trichiniüm auriculifolium bas, for the genus, a remarkable staminal 

 tube eight millimètres in length, and the ovary supported on a stipe of 

 neaiiy three millimètres. This striking specific character was not 

 noticed either by Moquin or Bentham. Its omission froni the descrip- 

 tions is no doubt what led Dr. Diels to describe it as a new species 

 recently under the appropriate name T. siphonandrum. 



The section Astrotricha, of Trichiniüm, is a convenient one but 

 should not include T. rotundifolium. The hairs on the leaves of this 

 species are very dense, tightly coiled, minutely articulate and reach a 

 léngth of two millimètres; it is allied to T. démenti. On the other hand 



