(i66) 



Alnns tenuifolia Nutt. River bank opposite Dawson (Wil- 

 liams). 



Alnus fruiicosa Rupr. Dawson (Williams) ; Ft. Selkirk 



(Tarleton). Agrees with Asiatic specimens so determined, 

 and seems distinct from Alnus Alno-Betula. 



Family Urticaceae. 

 Urtica gracilis Ait. Dawson (Williams). 



Family Chexopodiaceae. 



Blitum capitatum L. Dawson (Williams) ; near Sixty- 

 mile Creek (Tarleton). 



Family Polygonaceae. 



Polygonum amphibium L. Ft. Selkirk (Tarleton). 



Polygonum viviftarum L. Bennett City (Williams) ; above 

 Ft. Selkirk (Tarleton). 



Polygonum alfiinum Alaskanum Small. Klondike below 

 Bonanza (Williams) ; above Stewart River (Tarleton). 



Polygonum plurnosum Small sp. nov. 



Perennial, deep green. Stems erect, 1-3 dm. tall, simple, 

 glabrous : leaves few ; blades thickish, sparingly pubescent 

 beneath, those of the basal and lower stem-leaves ovate to 

 oblong-ovate or broadly oblong, 2-5 cm. long, blunt or mark- 

 edly obtuse, abruptly narrowed or subcordate at the base, 

 as long as their petioles or shorter, those of the upper stem- 

 leaves mostly oblong, short-petioled or nearly sessile, all 

 more or less revolute and with prominent nerves about the 

 edge : ocreae ample, prolonged into a narrowly funnelform 

 sheath, persistent : racemes cylindric, 2-6 cm. long, dense : 

 flowers persistent: calices rose-colored; lobes usualty 5, 

 broadly oblong or oval, 3.5-5 mm. long, obtuse or nearly 

 truncate at the apex, often inequilateral : stamens exserted ; 

 filaments slightly flattened ; anthers dark brown or blackish : 

 styles 3, elongated; stigmas capitate, minute: achenes 3- 

 angled, ovoid or oval, 3—3.5 mm. long. 



Related to Polygonum bistortoidcs Pursh ; but it is stouter 

 and more stocky in habit. It differs from P. bistortoidcs 

 very conspicuously in its leathery and pubescent leaf-blades, 



