278 PROCEEDINGS OF THE AMERICAN ACADEMY 



C. SESUVioiDES. DejDressed and spreading from a stout tap-root, 

 but seemingly not perennial, very succulent, leafy : leaves liuear- 

 spatulate, flattish, strong-edged, very obtuse, inch or more long, some 

 of them opposite : flowers in terminal and lateral subumbelliform clus- 

 ters : pedicels rather longer than calyx : sepals broadly ovate, obtuse, 

 nearly equalling the chartaceous capsule, as long as the 5 obovate 

 white petals : stamens 5 to 8 : style very short : stigma subcapitate, 

 undivided : seeds shining, minutely iiuncticulate, not at all strophiolate. 

 — Claytonia ambigua, Watson, Proc. Am. Acad. xvii. 365. Desert on 

 the lower part of the Colorado River, at Indio, and at El Rio, on the 

 Californian side, Lemmon, Parish. 



CLAYTONIA, Gronov. A specially North American genus, with 

 one singular outlier. Our species may be disposed as follows. 



§ 1. EuCLAYTOXiA. Perennial from a corm, thickened caudex and 

 tap-root, or rootstock, sending up radical leaves and scapes or flowering 

 stems bearing a single pair of opposite leaves (in one species some- 

 times a whorl of three, in another often alternate) : flowers usually not 

 ephemeral : stamens always 5 : seeds smooth and shining. 



* Co7-mose, the slender two-leaved stems and the few (seldom coeta- 

 neous) radical leaves from a deep globular corm : leaves linear to 

 oblong : petals light-rose, usually with deeper-colored veins. 



-t— Intermediate between true Claytonia and the Pachyrrhizea section 

 of Calandrinia ; the oblong-conical capsule being 12-16-seeded, 

 membranaceous, and dehiscent round the base : seeds smooth, not 

 at all strophiolate : pedicels of the cymose inflorescence mostly 

 subtended by small scarious bracts : anthesis seemingly ephemeral. 

 C. TRiPHYLLA, Watson, Bot. King Exp. 345. Leaves more fre- 

 quently a single pair than a whorl of three. The basally circumscis- 

 sile dehiscence was pointed out to us by Professor Henderson of Port- 

 land. Except for the strictly globose corm, I should refer this plant 

 to Calandrinia. 



H— -1— Typical Claytonia, the Spring Beauty of the Northern Atlantic 

 States : capsule (as in the whole genus except the preceding spe- 

 cies) 3-valved from the top and persistent: racemiform inflorescence 

 mainly bractless : pedicels recurved or drooping in fruit : seeds with 

 the small strophiole or white thickening at the hilum which is nearly 

 universal in this genus. 



C. ViRGiNiANA, L. Seems nearly to pass into the next. 



C. Caroliniaxa, Michx. An Atlantic species, extending to Sas- 



