﻿I'LVNT.E FENDLERIAN.2E. 15 



MALVACEAE. 



- 75. Malva borealis, Wallmann in Liljebl. Sv. Fl. sec. Fries. (M. rotundifolia 



(borealis), Fries, Novit. Fl. Suec. ed. 2. p. 218 ; Koch, Syn. Fl. Germ. p. 130. M. ro- 

 tundifolia 0. pusilla, Smith, DC. M. obtusa, Ton. &■ Gray! Fl. 1. p. 225.) Waste 

 places, Santa Fe ; June to August. — This species, which is well characterized by Fries, 

 Koch, &c., is distinguished from M. rotundifolia, Linn., by the very small corolla, and by 

 the transversely reticulated-rugose carpels, which are margined on the back, where they 

 meet each other by a more or less toothed edge. The calyx-lobes are also broader and 

 larger, especially in fruit, the leaves somewhat less lobed, and, in the New-Mexican and 

 Californian specimens (probably introduced from the Old World) the peduncles are very 

 much shorter, — a point which is not mentioned by European authors. The root is 

 strictly annual, while that of M. rotundifolia appears often to be perennial. Dr. Engel- 

 mann and myself have raised the plant from seeds taken from Fendler's specimens. 



76. Callirrhoe* involucrata. (Malva involucrata, Ton. fr Gray, Fl. 1. p. 226.) 



* A genus first indicated by Nuttall under this name, which was subsequently changed to that of Nuttallia, 

 but its diagnostic characters have not yet been given. Having been founded on exinvolucellate species, it 

 was at first only compared with Sida. But as involucellate species with the same habit became known, it was 

 proposed by Hooker {Jour. Bot. 1. p. 196) to refer the latter to Malva and the former to Sida. As the radi- 

 cle, however, proved to be inferior in all of them, they were all placed in the genus Malva in the Flora of 

 North America (except an obscure species, the characters of which were not entirely understood) ; and a new 

 genus was dedicated to Mr. Nuttall. A closer study of the American species thrown into Malva and Sida 

 reveals characters which induce me not only to restore this genus, but to propose some other genera. The 

 character which, on the whole, decides the question in favor of separating Callirrhoe from Malva, namely, the 

 transverse process in the carpel, has indeed been already observed by Dr. Torrey (Fl. N. Amer. I. p. 682) in 

 a single species which I now refer to it ; but it equally exists in the others, though much less conspicuously in 

 some of them. The leading character of the genus which I propose to call Sidalcea, namely, the double col- 

 umn separating into clusters of filaments, has also been noticed in the same work. The true Napcta, of 

 Clayton, with dioecious flowers, a naked calyx, and an inferior radicle, is a totally distinct genus, which (in 

 Man. Bot. North. United Stales, p. 69) I have already restored. There remain a set of ambiguous, perhaps 

 all American, species, which have been referred to Sida when the involucel was inconspicuous, deciduous, or 

 wanting, and to Malva when the involucel was manifest. From the latter, however, they differ by their capi- 

 tate stigmas (a character which, though generally attributed to Malva, is found in no European species) and 

 usually beaked fruit; and from Sida by the ascending ovule and inferior radicle. By separating these, under 

 the name of Mai cast rum (a name given by De Candolle to his division of Malva which comprises all the mo- 

 nospermous species, and which is no longer required now that the corresponding divisions are admitted gene- 

 ra), we leave both Malva and Sida much more natural and capable of exact definition. The genera in question 

 would be characterized as follows. 



