VOL. IV.] Contributions to Western Botany. 39 



would not yield. I then decided to take up the genus myself, 

 but lack of time has prevented till now. 



I find that the lobation and dentation of the leaves are of 

 little value, also the inflated calyx with connivent lobes, and the 

 shape of the seeds, as well as the pubescence of the pods. 

 The number of seeds in the carpels is very treacherous. The 

 stamens are almost always twenty, in A^. opidifotia in two ranks 

 and about forty, and the anthers broadly or narrowly oval, the 

 filaments are usually slightly wider at base only and about a line 

 long. The pubescence is always stellate or at least branched in 

 that fashion, but is very variable, and of almost no value. The 

 seeds are always oblique. All the leaves of the genus are three- 

 nerved, five-nerved only by accident. 



Taking the order as given by Mr. Greene X. opulifolia (L.) 

 Watson, comes first under the heading of "carpels inflated, 

 exserted from the calyx, divergent at apex, bivalvate-dehiscent." 

 The pods are divergent of necessity and are bivalvate-dehiscent 

 a little below the middle to the apex only and not throughout. 

 The range is given as from Canada and Florida to Kansas, while 

 the plant is rather common in Colorado, at least at the base of 

 the mountains on their eastern side at the junction with the 

 Plains. Mr. Greene gives the chief characters as " leaves round- 

 ovate, three-lobed, doubly crenate-serrate, carpels three, four, or 

 five, connate below, one-third inch long, much inflated, usually 

 two-seeded; seeds broadly obovoid." 



In my specimens from South Boulder, Colo., collected August 

 15, 1878, at an elevation of 6000 feet above the sea, and dis- 

 tributed as No. 914, I have one branch with the following leaves 

 on it, one leaf orbicular, not lobed, doubly crenate-serrate; two 

 leaves rhomboidal, lobeless, and doubly serrate as above, base 

 truncate; two leaves rhomboid-ovate, with a very broadly 

 cuneate base, barely three to five-lobed; all the above leaves 

 are rounded and very obtuse at apex; several leaves broadly 

 ovate and barely acute and distinctly lobed above and in other 

 cases below the middle; several others are ovate-lanceolate and 

 very acute and lobed as above. The leaves are from one-half to 

 two and one-half inches long. The pedicels are about an inch 

 long, densely stellate pubescent, the stalk of the stellate hair 



