GLOSSARY 423 



In'tine. The inner coat of the pollen grain. 



In'tra. A prefix meaning within. 



Intrapet'iolar. Applied to stipules that are between the petiole and the stem; 



also to buds that are beneath or inside of the base of the petiole. 

 Introrse'. Applied to anthers that face toward the gyncecium. 

 Intussuscep'tion. The formation of additional particles of protoplasm between 



those already present. 

 In'ulin. A carbohydrate substance isomeric with starch found in the Compos- 



itae and soma other families. 



In'volucre. A whorl (or whorls) of bracts subtending a flower or flower cluster. 

 Invol'ucel. A secondary involucre. 

 In'volute. Applied to the arrangement of leaves within a bud when they are 



rolled inward from both sides. 



JrritabiTity. That property of living matter whereby it responds to a stimulus. 

 Isog'amy. The union of sexual cells of similar form. 

 Isom'erous. Having the same number of parts in each whorl. 

 Isostem'onous. Having the stamens and petals each in one whorl and of the 



same number. 

 Isth'mus. Applied to the constricted portion between the two half cells in 



certain desmids. 



Karyokine'sis. Indirect nuclear division. 



Katab'olism. Destructive metabolism. 



Keel. Applied to a longitudinal ridge or elevation of cortical tissue of Senega 

 root which extends from the crown downward. Also applied to the two 

 inferior petals of a papilionaceous corolla which are more or less united into 

 a body resembling the keel of a boat. 



Knee. A form of knot which projects upward into the air from the roots of cer- 

 tain trees that grow in wet soil notably the bald cypress. 



Label'lum. The large lip-like lower petal in the flower of an orchid. 



La'biate. Two lipped. 



La'bium. The lower lip of a labiate flower. 



Lacin'iate. Applied to the margins of leaves which are deeply cut into irregular 

 narrow lobes. 



Lamel'la. A little plate. Applied to the layers of carbohydrate material in a 

 starch grain which surround the growing point; also to the gills of a toad- 

 stool. 



Lam'ina. The blade or expanded part of any leaf. 



La'nate. Covered with long curled wool-like hairs. 



Lan'ceolate. Lance shaped. 



La'tex. The milk juice of a plant. 



Laticif'erous. Applied to the latex carrying tissue of a plant. 



Latifo'liate. Possessing broad leaves. 



