72 PROCEEDINGS OF THE AMERICAN ACADEMY 



Michx.)." Until now no one has supposed that there were two jilants 

 in question, because no botanist had been attracted to them by seeing 

 the two plants in flower together. The specimens in Michaux's lierba- 

 rium are in fruit, or mainly so, but the phrase " flores albi octandri " 

 is appended to the character in the Flora. Michaux might have col- 

 lected and confounded the two ; but Professor Bureau, who kindly 

 compared sjiecimens for me, informs me that the Sedum in the herba- 

 rium of Michaux is unmixed with Diamorpha. The two plants are 

 different enough in aspect as well as in botanical characters. The 

 Sedum is the larger, earlier to blossom, of a pale and glaucous hue, 

 and, with its profusion of pure white flowers, is more conspicuous, even 

 showy ; the pods are abruptly pointed with a very short style, have the 

 iutroi'se dehiscence proper to the genus, and the seeds are oblong. 



The DiamorpJia^ of barely half the size, and with proportionally wider 

 leaves, has a dull purplish hue, extending more or less to the flowers ; 

 the sepals are distinct nearly to the base and narrower ; the petals 

 oval and obtuse ; the ovaries and pods tajjering from a broader base 

 into a subulate style ; the seeds round-oval ; and the cruciform union 

 of the pods at base and their ^Jeeuliar dorsal valvular dehiscence, 

 peculiar to the genus, are as described by Nuttall. • 



With these two plants was associated another rarity ; viz., the 

 Arenaria hrevifolia of Nuttall, in full blossom at the same season. 

 Mr. Canby also collected it, and very naturally took it for Arenaria 

 glabra Michx., to which, indeed, it is too closely related, but is probably 

 distinct. 



'^ Cleomella oocarpa. Diffusa, spithamtea ad subpedalem ; foliolis 

 oblongo-linearibus ; racemo sa^pissime densifloro ; bracteis inferioribus 

 foliis conformibus, superioribus simplicibus ; setulis stipularibus mani- 

 festis ; staminibus petala superantibus ; ovario apice 3-ovulato ; capsula 

 ovata lineam longa stylo breviusculo superata stipite (pedicelhim 

 subaequante) triplo breviore ; seminibus 1-2 Ifevibus. — Sterile saline 

 plains of Humboldt County, Nevada, Torrey, A. Gray ; and adobe 

 hillsides and plains on the borders of the Mesa Verde, South-west 

 Colorado, T. S. Brandegee, in Hayden's Exploration, 1875. This 

 has been confounded with 0. plocasperma, Watson, Bot. King Exp. 

 p. 33, which, thus far, has been collected only by Mr. Watson and 

 the Rev. R. Burgess, and has a larger and dilated rhombic pod, on 

 a stipe which generally little exceeds it in length, more numerous 

 and laterally inserted ovules, seeds with peculiar marking, shorter 

 stamens, -(fee. 



