CRUCIFER^. 



53 



ISATIS, L. (Woad.) ]\)d or silicle oviil or elliittical, flai, one-seeded ; 

 valves boat-shaped, sul)dehiscent ; cotyledons accuuil)ent. Biennial. 



1. I. tinctoria, L. (Woad.) Stem 4 icct Iiio;!!, half an inch in dianieter. 

 much hraiuhed. Leaves thick, liglit-green, oval, subclaspiug, ears rounded, 

 radical leaves petioled, and 10 to 12 indies 

 long and 6 wide, abundant, giving the 

 plant a coarse appearance. Flowers small, 

 yellow, and in terminal panicles. Ai»i)ear- 

 ing in July. 



Gcorp-aphi/. — Woad is indigenous 

 throughout the continent of Europe, and 

 (ireat Britain. It is cultivated in Eng- 

 land, Sweden, Germany, Switzerland, and 

 in the Azores and Canary Islands. 



Etymology and History. — Isatis is de- 

 rived from the Greek word lo-o^w, make 

 smooth or even, because it was supposed 

 to remove roughness of the skin. It has 

 been called (jlaslum, from the Celtic word 

 tjlas, blue. The ancient Britons, at the 

 time of the invasion by Julius Ci^sar, 

 adorned their bodies by painting the forms 

 of animals and other objects on them with 

 woad, hence the Romans gave them the 

 name of Picts, or pictured men. 



Woad imparts a permanent blue color, 

 the shade depending upon the quantity, and manner of using it. 

 of giving a very dark l)lue, approaching a blue-ltlack. 



Cue. — Notwithstanding the inroads tliat indigo has made upon the use of 

 woad, on account of the permanency t)f the color imparted by woad it still 

 holds an important place among coloring substances. Dyers are in the habit 

 of mixing it with indigo ; the dyes are said to coalesce, and strengthen each 

 other. Its use is rapidly dying out in England. 



Isatis tinctoria (Woad) 



It is cajiable 



NASTURTIUM, R. Br. Sepals 4. regular, and equal at base. 

 Petals regular, white, seed-vessel or silique tapering, cylindrical, 

 short, and cuived upwards. Seeds small, irregularly arranged in a 

 double row. Leaves alternate. Herbs which delight in wet places, 

 or in the edges of the waters of slowly flowing streams. 



1. N. officinale, R. Rr. (Water Cress.) Stem perennial. 6 to 18 inches long, 

 branched, prostrate, and assurgent. Leaves pinnately divided ; leaflets very 

 inconstant, ranging in number from '? to h pairs, and a terminal one, rounded, 

 usually entire, and glabrous, occasionally sinuately toothed. Flowers in June. 

 Fruits in July. 



Geography. — The geographical distribution of this plant is very wide, as 

 is the ca!<e with all economic plants which follow colonization. It grows 

 all over Europe, in Palestine, Hindustan, Japan, tlie islands of the Atlantic 

 and the Pacific, wherever I-'uropean colonies have been established. 



Etymology. — Na.<itnrtiin7i is derived from the Latin nasus, the nose, and tortu.'^, 

 a tivisting, said to be due to tlie effect which its pungency has upon the nose 



