RvDBERG : Some Generic Segregations 277 



I I. T. densa (Greene) ; M. dcnsa Greene, Pittonia, 3 : 99. 1896. 



12. T. pumila (Nutt.) ; M. piimila Nutt. ; Terr. & Gray, Fl. N. 

 Am. I : 535. 1840. 



13. T. chrysantha (Engelm.) ; M. chrysautha luigelm. ; Brand. 

 Bull. U. S. Geol. Surv. Terr. 2 : 237. 1876 ; M. lutca Greene, 

 Pittonia, 3 : 99. 1896. 



14. T. humilis (A. Gray) ; M. iiiit/ii/IoraxSiY. hiniii/is A. Gray, PI. 

 Wright. I : 74. 1852. 



15. T. multiflora (Nutt.) ; Bartonia viultijiora Nutt. Jour. Acad. 

 Phila. II. I : 180. 1847. 



16. T. perennis (Wooton) ; M. perennis Wooton, Bull. Torrey 

 Club, 25 : 260. 1898. 



17.* T. MULTic.\ULis Osterhout, Bull. Torrey Club, 30 : 236. 1903. 



AcROLASiA Presl. Rel. Haenk. 2: 39. 1831 



TradiypJiytum Nutt. ; Torr. & Gray, Fl. N. Am. i : 533. 1840. 



This genus was established on a Chilian species, A. bartoni- 

 oidcs Presl, which has fewer ovules (12) and fewer stamens than 

 its North American allies, but the structure of the ovary and seeds 

 is the same. All the species are annuals and characterized by the 

 long cylindric capsules, the filiform placentae and the muricate 

 more or less prismatic seeds. Most of the species are small- 

 flowered, with linear, lanceolate or ovate-oblong, laciniate, dentate 

 or more rarely entire sessile leaves. The following North Ameri- 

 can species belong here : 



1. A. congesta (Nutt.); M. congesta Nutt; Torr. & Gray, Fl. 

 N. Am. I : 534. 1840; Trachypliyttim congestuvi Nutt. ; Torr. 

 & Gray, 1. c. 



2. A. ctenophora ; M. ctenophora Rydb. Bull. Torrey Club, 28 : 

 11- 1901- 



3. A. Tweed5ri ; M. Tioccdyi Rydb. Mem. N. Y. Bot. Gard. i : 

 271. 1900. 



4. A. albicaulis (Dougl.) ; M. albicanlis Dougl. ; Hook. Fl. Bor. 

 Am. I : 222. 1833 ; Bartonia albicaulis Hook. 1. c. 



5. A. tenerrima ; M. tenerrima Rydb. Mem. N. Y. Bot. Gard. 

 I : 271. 1900. 



