— 253 — 



Ny Litteratur. 



Dansk Skovforenings Tidsskrift, tillige forstlig Diskussions- 

 forenings Organ. 1. Hæfte 1916. 



Dansk Skovforening, som hidtil har haft det af Professor G. V. Prytz 

 udgivne „Tidsskrift for Skovvæsen" som Organ, har fra Begyndelsen af 

 1916 begyndt at udgive sit eget Tidsskrift, hvoraf det første Hefte fore- 

 ligger. Af dettes Artikler skal fremhæves følgende. P. E. M filler: 

 Skotsk Fyr, en Rejseoptegnelse. A. Oppermann: Det danske Hedesel- 

 skab 1866 — 1916. Joh s. Helms: Saaning af Lyng paa Himmelbjærg. 



The Occurrence of Polygonum acadiense in Denmark. 



By M. L. Fernald. 



In 1914 the writer and his assistant, Mr. Harold St. John, collected 

 on a gravelly strand of Bras d'Or Lake, Gape Breton, Nova Scotia (Canada) 

 a prostrate Polygonum which was obviously related to P. Raji Bab.; but 

 which differed in so many essential characters that is was described as 

 a new species, P. acadiense Fernald 1 ). The plant was then supposed to 

 be an endemic Canadian representative of P. Raji y but recently, happening 

 upon the plate of „P. Raji" in Flora Danica (t. 2772), the writer has 

 been surprised to note that, instead of representing Babington's species, 

 it is a very characteristic illustration of P. acadiense. In all its essential 

 details : habit, ochreae, leaves, calyces and achenes, the Flora Danica plate, 

 representing Danish material, exactly portrays the Nova Scotian species ; 

 and in its ochreae, leaves, calyces and achenes it departs, as does P. aca- 

 diense, from the British material of P. Raji. The latter species is well 

 illustrated in Engl. Bot. Suppl. t. 2805; in Beichenbach, Icon. Fl. Germ. 

 XXIV. t. 204; and its essential features are suggested in Gambr. Brit. 

 Fl. II. t. 131. 



The diagnostic characters of P acadiense and the points in which 

 it differs from P. Raji are indicated by the following extracts from the 

 original account of the plant: 



Polygonum acadiense, n. sp., annuum prostratum paulo vel vix glau- 

 cum rubro-viride, caulibus gracilibus, internodiis 1,5 — 3,5 cm longis; 

 ochreis internodo multo brevioribus 1— 1,3 cm longis albino-hyalinis basi 

 purpurascentibus remote circa 6-nerviis ovata-oblongis acutis adpressis 

 demum bipartitis lacerisque; foliis lineari-oblanceolatis acutis submembra- 

 naceis subtus 1-nerviis, primariis 2 — 4,5 cm longis 2 — 7 mm latis petiolo 

 3 — 8 mm longo; axillis 1 — 3-fïoris ; pedicellis calycem subaequantibus 

 apice valde articulatis ; calyce 4 mm longo turbinato-campanulato profunde 

 4 — 5 partito, lobis oblongis obtusis subaequalibus margine albido- vel 

 roseo-petaloideo basi non angustatis; achenio olivaceo lucido ovato-lan- 

 ceolato 6 mm longo 2 — 3 mm lato a calyce arete amplectente valde 



exserto — NovaScotia: gravelly strand of Bras d'Or Lake, 



Grand Narrows, Gape Breton, July 20, 1914. Fernald & St. Joh m 

 no. 11,042 (type in Gray Herbarium). 



x ) Fernald, Rhodora, XVI. 188 (1914). 



