Wall. — Distribution of Senecio saxifragoides Hook. f. 201 



The distribution of S: lagopus is given by all authorities as from the 

 Ruahine Mountains to South Canterbury. 



The original description of S. lagopus by Raoul, and his plate (Choix, 

 pi. 17), must here be referred to, as of the greatest importance in the study 

 of the two species. In describing the petiole of S. lagopus, Raoul says, 

 " Petioli . . . canaliculati in vaginam semiamplexicaulem dense lana- 

 tam dilatati " ; and in describing the leaf he says, " Folia . . . pilis 

 rigidis grossis, spinescentibus praesertim ad margines inspersa." His plate 

 shows a plant with four large and several small leaves. Of the four large 

 leaves three are glabrate (as the old leaves of both S. lagopus and S. saxi- 

 fragoides always are) : the fourth bears the characteristic " bristles " very 

 thickly close to the margin all round the leaf, or nearly so, and near the 

 apex ; less thickly upon the upper third of the leaf or thereabout ; the 

 lower part of the leaf bears the hairs only, very thickly distributed. The 

 hairs and bristles occur together over some portions of the leaf, about the 

 middle and towards the apex, but at the apex itself and in its immediate 

 neighbourhood the bristles alone occur. The dual occurrence of hair and 

 bristle* on the same leaf, which no subsequent authority describes at all, 

 will appear to be of great importance to this inquiry ; and it may be added 

 that my descriptions of the variant forms of S. saxifragoides given below 

 were fully made before I had seen Raoul's plate. 



The species are further thus referred to by Laing and Blackwell (Plants 

 of New Zealand, pp. 437-38, 1906) : ' The handsome S. saxifragoides, sup 

 posed by Kirk to be confined to Banks Peninsula, is undoubtedly the 

 typical S. lagopus of Raoul. It still produces its large-leaved rosettes on 

 the southern faces of cliffs, where Raoul found it, near Akaroa. It is 

 also plentiful behind Lyttelton, often growing in altogether inaccessible 

 localities, and it is the only Senecio which haunts these situations on the 

 Peninsula." 



2. Special ^Characters of the Two Species [under Consideration. 



1. All round the margin of the leaf of S. lagopus, S. saxifragoides, and 

 S. belUdioides occur at very regular intervals — i.e., at the ends of the veins 

 — rounded glandular protuberances of a very dark red or purple colour. 

 Microscopical examination shows these to be typical hydathodes. 



2. The petiole of the leaf of S. lagopus bears quantities of dark-red or 

 purple bristles, generally spotted or pied with white ; these are continued 

 up the back of the midrib nearly to the apex of the leaf, and are also 

 present along the margin all round the leaf. 



3. S. saxifragoides also shows this purple or pied bristle upon the petiole 

 and the back of the midrib exactly as in S. lagopus, and also bears this 

 bristle all round the margin of the leaf, making a continuous fringe. The 

 young leaves of S. saxifragoides have yellow marginal bristles, which change 

 gradually into purple and continue to deepen in colour up to maturity. 

 The yellow bristle, however, is usually present together with the purple, 

 the yellow being upon the upper surface of the leaf just within the margin, 

 the purple being upon the margin itself ; but they are sometimes more or 

 less mixed together. 



4. Forms of Senecio lagopus and Senecio saxifragoides which grow in 

 situations shaded by other vegetation, as among long tussock-grass, or on 



* The term " bristle " is kept throughout, as that employed by previous authorities 

 though the organ is really a glandular hair. 



