274 ON THE STAMINAL ARRANGEMENTS IN 
developed as a petal, so-called. When there are five stamens in the 
festoon, the central stamen must be regarded as an interstaminal lobe, 
analogous to interpetiolar stipules—to the intersepaline lobes in some 
species of Campanula, in Nemophila, and in Potentilla itself (the so- 
called epicalyx), or to the interpetaline lobes of the corolla of Solda- 
nella.* 
I have not been able to examine any of the nearest allies of Poten- 
tilla fruticosa. P. glabra is grown in the Botanic Garden here, but 
has not flowered for some years. In Potentilla rupestris, however, I 
have found an andrecium in all respects similar to that of P. fruticosa ; 
and, from Lindley’s description of the stamens of P. arguta, an ally of 
P. rupestris, as “about 25, filaments inserted on the margin of a five- 
lobed glandular disk which surrounds the base of the receptacle” (Bot. 
79), I suspect that the same arrangement occurs there also. 
In connection with the foregoing investigation, I have been led to 
examine the staminal arrangements in a considerable number of species 
of Potentilla, in all about twenty-nine. The staminal arrangements 
in these species may be reduced under three heads or types. 
Type I., where there are 20 stamens (16 where the flower is 4-nary) : 
one scperpbiied to each sepal, one to each petal, and one on either side 
of each petal (Plate LII. Fig. 1). This is, apparently, by far the 
commonest arrangement in the genus, as indeed in the whole family 
Rosacee. 
Type IL, where there are 30 stamens. Differing from the last by 
having three stamens, instead of one, in front of each sepal (Plate LU. 
"ig. 2). is rien s in the forms falling under P. hirta of De Can- 
dolle's * Prodromus. 
ype IIL, where there are 25 stamens (arranged in five festoons, 
extending from petal to petal). Differing from Type II. chiefly in the 
absence of oppositipetalous stamens (Plate LII. Fig. 3). This occurs 
in P. fruticosa, P. rupestris, and probably in several others. 
* The corolla of Soldanella presents ten lobes, alternately trifid and entire. 
The five trifid lobes are the petals ; the five entire ones the interpetaline lobes. 
interpetaline sinus; and lastly, yore Tend eve of the petals appea 
development he ponds, of course, to a basifugal e ese grin of leaf lobes, 
and differs in this respect from what occurs in the co mpound stamens of Po- 
tentilla, which would correspond to a basipetal on 
