106 LINACEiE. 



Eighty-one species of the typical genus are enunierated in the recent 

 monograph of Dr. Planchon, which are so distributed that there are some 

 in every district of the temperate zone ; while within the tropics they are 

 found only where elevation gives an equivalent climate. There are none in 

 the frigid zones. Five or six species are indigenous to the United States, 

 of which L. Virginianum is the most widely diffused. The others belong 

 principally to the region west of the Mississippi, especially southward. Dr. 

 Planchon divides the genus into four subgenera and eight subordinate sec- 

 tions. Reinwardtia, Duinort., comprises the trigynous shrubby Linums of 

 the earlier authors, all natives of India. 



