314 The Ohio Journal of Science [Vol. XVII, No. 8, 



many, 2-5 in. long, more or less lobed; stem-leaves few, sessile, 

 sagittate, dentate or entire. Flowers begin to bloom when the 

 stem is very short, and the stem lengthens as the flowers open. 

 Blooms throughout the growing season. 



Naturalized from Europe. General and abundant. 



7. Neslia Desv. Ball-mustard. 



Annual or biennial erect branching herbs, with entire leaves 

 and small yellow flowers in racemes. Silicles small, round, 

 indehiscent, 1-celled, 1-seeded. Style slender. A monotypic 

 genus. 



1. Neslia paniculata(L.) Desv. Ball-mustard. Stem slender, 

 branched at the inflorescence, rough-hispid with branched 

 hairs, 1-2 ft. high; leaves lanceolate, acute, sagittate-clasping, 

 1-2 in. long; racemes elongated; pods globose, reticulated, 

 spreading. 



In waste places and grain fields, naturalized from Europe. 

 Escaped in Lake County. 



8. Armoracia Gaertn. Horseradish. 



Tall perennial glabrous herbs from large and long pungent 

 roots, with large leaves and white flowers in paniculate racemes. 

 Silicles nearly globular, style short. Seeds few, in 2 rows in 

 each cavity, wingless. 



1. Armoracia armoracia (L.) Britt. Horseradish. Stems 

 erect, 2-3 ft. high, leafy; basal leaves rough but glabrous, 

 wavy, crenate or even pinnatified, 6-12 in. long, petioled; 

 stem-leaves smaller, lanceolate, crenate or dentate, sessile; 

 racemes terminal and axillary, flowers large; pods seldom 

 matured. 



Escaped from gardens into moist ground and spreading by 

 the roots which furnish the well-known sauce. Naturalized 

 from Europe. General. 



9. Neobeckia Greene. Lake Water-cress. 



Branching perennial aquatic herbs, with finely dissected 

 immersed leaves and oblong emersed leaves. Flowers large, 

 white racemose, petals longer than the calyx. Silicles ovoid. 

 Seed few, in 2 rows in each cavity. 



A monotypic genus of eastern North America. 



1. Neobeckia aquatica (Eat.) Britt. Lake Water-cress. 

 Stems 1-2 ft. long; immersed leaves 2-6 in. long, pinnately 



