86 ILLUSTRATIONS OP 



It may be urged, that in Schwenkia the total number of lobes 

 in^the border being generally more than five, and the suppression 

 or* diminution of some of these and of the stamens being of fre- 

 quent occurrence, are features quite foreign to the Solanacea. 

 But in Hebecladus and Dunalia we meet with five intermediate 

 teeth between the lobes of the border, and in Nectouxia, an 

 annular 10-toothed ring is placed in the mouth of the corolla, 

 within the line of origin of the five segments, forming thus a 

 corona, closely analogous in its nature to those more expanded 

 petaloid segments which Mr. Bentham describes as appendi- 

 ciform processes in Schwenkia. In this genus the stamens are 

 always five in number, and are situated below the middle or near 

 the base of the tube of the corolla ; of these, two, or sometimes 

 four, are antheriferous and reach the mouth of the tube, while 

 three, two, or one, are occasionally sterile or anantherous, the 

 filaments in such case being sometimes short and rudimentary. 

 In many Solanaceous plants there is often a difference in the size 

 of the stamens, and this becomes a constant feature of the section 

 Nyderium of the genus Solarium, where three of them are always 

 considerably larger than the two others, which are sometimes 

 almost sterile. The suppression of some of the anthers, and of 

 a portion of the glandular-looking lobes (true segments) of its 

 border in Schwenkia, must be considered one of those exceptional 

 cases which are occasionally met with in a great many orders ; 

 it serves as a point of osculation between the Solanacea and 

 Scrophulariacea, in which latter family, the want of symmetry 

 in its parts, and a total or partial suppression of one of its 

 stamens, form almost universal characters. On the other hand, 

 we meet in the same family several cases where the corolla is 

 pentamerous, and as regularly symmetrical in its parts as in 

 Solanacea ; thus in Capraria {Xuaresia, R. & P.), we find a 

 corolla with a border of five equal lobes and five equal stamens ; 

 80 also in some species of Verbascum, and in Sibthorpia, where 

 likewise the stamens are generally five, and equal in number to 

 the regular segments of the border, although rarely four or eight 

 occur. In my definition of Schwenkia, as given below, I have 

 modified somewhat Mr. Bentham's view of the structure of the 

 corolla, considering the expanded segments of the border to be 

 analogous in their nature to the corona of Nectouxia. 



Referring to the question of aestivation, it will be seen that in 

 the sections Chatochilus, Euschwenkia, and Brachyhelus, where 

 the segments of the corona are small, they are valvately con- 

 joined in bud by their floccose margins into a short cone, that closes 

 the mouth of the tube, the lobes lying over them, and pointed 

 toward the axis : in Brachyhelus, these lobes, which are several 

 times longer than the toothed segments, soon become approximated 



