





CURRENT LITERATURE 



NOTES FOR STUDENTS 



Taxonomic notes. — Engler 1 has described a new genus (Hieronxmusia) 

 of Saxifragaceae from South America (Argentina and Bolivia). It was 

 referred first to Saxijraga (S. alchemilloides) and later to Suksdorjia. 



Schlechter, 2 in continuation of his studies of orchids, has described 19 

 new species, representing 9 genera, chiefly collected in Argentina by Dusen. 



St. John 3 has described a new genus (Phanerotaenia) of Umbelliferae, 

 based on Poly taenia Nuttallii texana C. and R., of Texas and Oklahoma. 



Setchell and Gardner 4 have begun the publication of the marine algae 

 of the Pacific Coast, the first part including the blue-green algae. The group 

 as presented contains 30 genera, representing 6 families. Of the 93 species 

 included, 35 are described as new. — J. M. C. 



Polycotylous seedlings. — Miss Bexon 5 has found that Centranthus ruber 

 (Valerianceae) develops a remarkably high proportion of polycotylous seedlings. 

 From two square yards of soil in which self-sown seeds of this species were 

 germinating, 87 polycotylous specimens were obtained and studied. They 

 are grouped as hemitricotyls, tricotyls, hemitetracotyls, and tetracotyls, 

 terms which are self-explanatory. The vascular anatomy of these various 

 conditions was investigated, with some interesting results. A " twinned " 

 seedling was of special interest, the twinning being due either to the fusion of 

 two distinct embryos, or to the partial separation of the product of the embryo 

 initial. — J. M. C. 



Unusual monocotyledonous roots. — Miss Spratt* has discovered some 

 interesting anomalies in the roots of some monocotyledons. In Dracaena there 



1 Engler, A., Hirronymusia Engl., eine neue Gattung der Saxifragaceen. 

 Xotizbl. Konigl. Bot. Gart. 7:265-267. Jig. I. 1918. 



2 Schlechter, R., III. Orchidaceae novae, in caldariis Horti Dahlemensis 

 cultae. Notizbl. Konigl. Bot. Gart. 7:268-280. 1918. 



« St. John, H., Phanerotaenia, a new genus of Umbelliferae. Rhodora 21:181- 

 183. 1919. 



* Setchell, W. A., and Gardner V. L., The marine algae of the Pacific Coast 

 of North America. I. Myxophyceae. Univ. Calif. Publ. Bot. 8:1-138. pis. 1-8. 1919. 



5 Bexon, Dorothy, Observations on the anatomy of some polycotylous seed- 

 lings of Centranthus ruber. Ann. Botany 34:81-94. Jigs. 9. 1920. 



6 Spratt, Amy Vera, Some anomalies in monocotyledonous roots. Ann. Botany 

 34:99-105. pi. 3. Jig. 1. 1920. 



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