542 MR. C. BUCKNALL : A REVISION 
different directions, and occupying different areas. The Aubagne plants, of 
which there is a good sheet at Kew, all, unfortunately, without roots, at first 
appeared to me to be young specimens of S. tuberosum, but, on comparing them 
with plants of that species in the same stage ot growth, I found that they were 
not only very different in habit, but possessed in a marked degree the cha- 
racters which Koch gives as distinguishing S. mediterraneum, As the locality, 
Aubagne, is only twenty miles or so from Toulon, in the neighbourhood of 
which town Koch's plant was found, there is every reason for the belief that 
this is at least a form of S. mediterraneum. 
The Aubagne plants are distinguished from S. tuberosum by the lower and 
more compact growth, by the flexuous stem which is bent in alternate 
directions at each node, and by the comparatively large cordate or rounded 
lower leaves which are broader than, but not so long as, the succeeding ones. 
The size of the flowers is only a little less than is usual in S. tuberosum, 
and in this point the Aubagne plants do not correspond with Koch's 
statement that they are only half the size of those of that species. This 
has been copied by succeeding authors as a character of S. mediterraneum, 
but, as the size of the flower is often variable in this genus, this need not be 
an obstacle to the acceptance of these plants as Koch’s species. The winged 
amplexicaul petioles form a well-marked feature of the Aubagne plants, and 
in this Koch states that S. mediterraneum differs from S. tuberosum. This 
character is, however, also found in the latter species, as well as in other 
members of the group, more especially in the primordial leaves, but it is not 
generally so conspicuous as in 5, mediterraneum. 
The plant gathered by Miss Maud Law at Vallauris, which is about 
100 miles from Aubagne, differs in the lower leaves being gradually 
attenuated into the petiole, and in the taller and straighter stem. It may 
be regarded as intermediate between S. tuberosum and S. mediterraneum. 
21. 5. GussoxEt, Schultz, in Arch. Fl. (1874) p. lviii. 
Radix repens, gracilis, teres, tubercula subrotunda invicem gerens. Caulis 
simplex vel apice bifidus, gracilis, parce retrorsum pilosus. Folia pilosa, 
infima minima, lanceolata vel elliptica, in petiolum anguste alatum, basi 
amplexicaulem attenuata, media multo majora, ovata, elliptica vel oblonga, 
in petiolum brevem, late alatum subattenuata, suprema ovata, sessilia. Racemi 
pauciflori. /achis pedicellique pubescentes et parce pilosi. Calyx ad tertiam 
partem inferiorem in lacinias lanceolatas acutas ciliatas fissus. Corolla albida, 
усет subtriplo excedens. Fornices lanceolati, acuti, inclusi, stamina 
longe excedentes. Anthere basi apiculatze, filamentis subduplo longiores. 
Nueule .... 
Tubereula 1-2 em. et ultra diam.: caulis 2—3 dem. altus; folia infima 
L5 Z em. longa, 0°8—1°5 em. lata, media 8-9 em. longa, 3:5 em. lata, vel 
