276 PROCEEDINGS OF THE AMERICAN ACADEMY 



T. CALYCiNUM, Engelm., in Wisliz. Rep. 4 ; a species of the Upper 

 Arkansas region. 



T. PARViFLORUM, Nutt., is palcr-flowered and peutandrous. T. 

 confertijiorum, Greene, in Bull. Torr. Club, viii. 121, appears to be 

 a form of this species. 



LEWISIA, Pursh. Sir Wm. Hooker was correct in figuring the 

 embryo of L. rediviva as with accumhent cotyledons. So far as we 

 know, it is not so in any other Portulacaceous plant, not even in 

 L. brachycalyx, Engelm. (a badly chosen name), which connects the 

 genus very closely with Calandrinia. In fact, the tetrasepalous calyx 

 makes the only difference. 



CALANDRINIA, HBK., was founded upon two species. The 

 type is C. caulescens, an annual, with leafy stem and 3-valved persist- 

 ent capsule. Of the other species, the stemless and very thick-rooted 

 C. acaults, the fruit was not known. It proves to be thin-walled, cir- 

 cumscissile at the very base, thence splitting upward more or less ; 

 indeed, it is just that of Lewisia. We have a good series of North 

 American species of the same type ; but the group cannot properly be 

 regarded as generic, for the same dehiscence occurs in several Chilian 

 caulescent perennial species of unlike habit, and probably in some 

 annuals. Of this marked Lewisioid section, Pachyrrhizea, I recog- 

 nize the following species. 



1. With seeds not at all or not manifestly strophiolate, the testa mostly 



very smooth and shining. 

 a. Low, with large fleshy root (caudex and root together) napiform or 

 conical : scapes 1-3-flowered, not surpassing the linear or spatulate 

 radical leaves. 



C. acaults, HBK., of Mexico and northern part of the Andes. 

 C. Nkvadensis, Gray, Proc. Am. Acad. viii. 623, and 

 C. PYGM^A, Gray, 1. c, species of the Rocky Mountains and the 

 Western sierras. 



h. Scapes or scapiform flowering stems a span or two high from a mul- 

 ticipital caudex and long thick root, paniculately several-many-flow- 

 ered : leaves mainly rosulate on the caudex, very fleshy : sepals (as 

 in the last preceding species) rounded or truncate, erose-dentate or 

 fimbriate, very much shorter than the obovate rose-red petals. 



C. Cotyledon, Watson, Proc. Am. Acad. xx. 355. INfountains on 

 the borders of California and Oregon. O. oppositifolia, Watson, 1. c, 

 also discovered by Mr. Howell in the same district, is thought to be a 



