58 TAXONOMY OF VASCULAR PLANTS [Bot. Absts., Vol. VI, 



combinations occur: Pittosporum dzumacense, Psychotria microglossa Baill. (Uragoga micro- 

 glossa Baill.), Chrysophyllum Francii Guillaum. & Dubard, and Calycorectes ovigerus (Euge- 

 nia ovigera Brong. & Gris.). — E. B. Payson. 



414. Heribert-Nilsson, Nils. Experimentelle Studien uber Variabilitat, Spaltung, Art- 

 bildung und Evolution in der Gattung Salix. [Experimental studies on variability, division, 

 species-formation and evolution in the genus Salix.] Acta Univ. Lund [Acta Reg. Soc. Physiog. 

 Lund N. S. 29". No. 28.] N. S. 14 (Avd. 2 28 ) : 1-145. 1918.— This is an extensive account 

 of experimental studies in Salix. Many hybrids are designated, described and illustrated. 

 No new species are described. — E. B. Payson. 



415. Hitchcock, A. S. History of the Mexican grass, Ixophorus unisetus. Jour. Wash- 

 ington [D. C.] Acad. Sci. 9: 546-551. 1919. — The nomenclatorial history of this species, which 

 has previously been described under five different specific names and referred to four genera, 

 is reviewed and its synonymy cited. — Helen M. Gilkey. 



416. Hole, R. S. A new species of Tamarix. Indian Forester 45: 247-249. 1919. — 

 Tamarix Troupii is the name given to a new species found in the United Provinces, briefly 

 described here. — E. N. Manns. 



417. Hopkins, L. S. The occurrence and distribution of Vasey's pondweed in North- 

 eastern Ohio. Torreya 19: 243-244. 1919. — Potamotgeton Vaseyi Robbins was first collected 

 in Ohio by the writer at Brady's Lake, Portage County, June 22, 1912. It has since been 

 found in Ashtabula County in 1918, and at Sandy Lake, Portage County in 1919. It is 

 not included in Schaffner's "Ohio Catalogue of Vascular Plants." The descriptions in 

 the current manuals are corrected as follows: (1) Fruiting stems are not rare, (2) the larger 

 leaves do not always float, (3) fruiting stems are not limited to shallow water. — J. C. Nelson, 



418. Jackson, A. B., and A. J. Wilmott. Barbarea rivularis in Britain. Jour. Botany 

 57: 304-306. 1919.— This paper is a reply to one by Marshall (Jour. Botany 57: 211. 1919). 

 Marshall was in error in recording B. rivularis as new to Britain. It was shown (Jour. Bot- 

 any 54: 202. 1916) that B. rivularis is B. vulgaris var. silvestris Fr., a form not uncommon in 

 Britain. The length of the silique in these various forms, and in a specimen sent to the 

 authors by Marshall, is discussed. The strict-fruited form of B. vulgaris has frequently been 

 confused with B. stricta, but they can scarcely be confused by one who knows them in the 

 field. Marshall has overlooked the important contribution by Spragtje and Hutchinson 

 (Jour. Botany 46: 106. 1908) where the two forms are clearly differentiated. The shape 

 and size of the lateral lobe of the leaf is of minor importance. Stme may have confused 

 B. stricta and B. rivularis, as Marshall says, but this is uncertain. — K. M. Wiegand. 



419. Jauch, Berthe. Quelques points de l'anatomie et de la biologie des Polygalacees. 

 [Certain details of the anatomy and biology of Polygalaceae.] Bull. Soc. Bot. Geneve 10: 47-84. 

 15 fig. 1918. — A study of Polygala Chamaebuxus and closely related species leads the author 

 to consider the family Xanthophyllaceae of Gagnepain as untenable. Xanthophyllum is 

 retained, as indicated by Chodat, in the family Polygalaceae because of the structure of the 

 flower and the characteristic pollen. The stamens of Polygalaceae are four-celled, but by 

 reduction of the inferior cells a type with two or three cells may be obtained. The four-celled 

 type is the more primitive. The ovules of Polygalaceae receive parietal vascular bundles. 

 The ovary is divided into two cells by a wall and the placentation is parietal although appar- 

 ently axillary. — W. H. Emig. 



420. Lam, H. J. The Verbenaceae of the Malayan Archipelago, together with those from 

 the Malayan Peninsula, the Philippines, the Bismark- Archipelago, and the Palau- and Caroline 

 Islands. 371 p., 3 pi. Groningen, March 31, 1919. [Doctorate Dissertation.]— This work 

 represents a critical revision of the family based on a study of collections in the herbaria of 

 Leiden, Utrecht, and Berlin. Keys for determination and descriptions are given for 28 genera 



