72 PROCEEDINGS OF THE AMERICAN ACADEMY 



Miflix.)." Until now no one has supposed that there were two plants 

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

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

 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 specimens for me, informs me that the Sedum in the herba- 

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

 diflTerent enough in aspect as well as in botanical characters. Tlie 

 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 

 introrse dehiscence proper to the genus, and the seeds are oblong. 



The Diamorpua, 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 tlie base and narrower ; the petals 

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

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

 of the pods at base and their peculiar dorsal valvular dehiscence, 

 peculiar to the genus, are as described by Nuttall. 



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

 Arenaria hrevifulia 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, spithama^a ad subpedalem ; foliolis 

 oblongo-linearibus ; racemo saspissime densifloro ; bi'acteis inferioi'ibus 

 foliis conformibus, superioribus simplicibus ; setulis stipularibus mani- 

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

 ovata lineam longa stylo breviusculo superata stipite (pedicellum 

 suba^quante) triplo breviore ; seminibus 1-2 hevibus. — 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 Haydi^i's Exploration, 1875. This 

 has been confounded with C. plocasperma, Watson, Bot. King Kxp. 

 p. 33, which, thus far, has been collected only by I\Ir. Watson and 

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

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

 and laterally inserted ovules, seeds with peculiar marking, hliortcr 

 stamens. &c. 



