EXPLANATION OF THE PLATES. 335 



with the flowers in axillary clusters, having the appearance of 

 bein<j verticillated. a. The upper lip of the monopctalous 

 corolla, which is 2-lobed. b. The lower lip, with 3 lobes. 

 c. The anthers converging in opposite pairs, so as to put on 

 the appearance of a cross, a character given as the peculiar 

 mark of the genus, d. The calyx, in the bottom of which is 

 seated the 4 naked seeds. 



Fig. 2. — A flower of the Teucrium frutkans. a. The lower 

 lip in 3 lobes, the central lobe much larger. The upper lip 

 of 2 lobes, cleft, and b. The stamens coming out of the 

 fissure. 



Fig. 3. — a. The personate or masked flower of the Toad-flax 

 (Antirrhinum Linaria), the palate being closed by the con- 

 vex projection of the lower lip, which below terminates in a 

 spur. b. The disposition of the stamens converging by pairs 

 of unequal length ; near the base of the shorter pair there is 

 the rudiment of a 5th stamen, c. The capsule of 2 cells 

 opening on either side by a number of reflected teeth, the dis- 

 sepiment and adhering style presenting the appearance of a 

 spur. 



Fig. 4. — a. The Peloria or regularized and perfected flower of the 

 Toad-flax, having a regular 5-lobed reflected border, 5 equal 

 stamens, and 5 equidistant spurs below, b. The same laid open 

 to show the stamens. 



Fig. 5. — a. The flower of Prunella vulgaris, or Self-heal. b. The 

 stamens characterized by their forked filaments, one of the 

 extremities only producing an anther. 



Fig. 6. — A small branch of Erinus alpinus, in which the didyna- 

 mous flower has a nearly equal and regular border. 



PLATE V. 



UMBELLIFEROUS PLANTS. 



Fig. 1. — A branch of the American Coriander with triternately dis- 

 sected, narrow cleft leaves, (Coriandrum * americanum) .\ 

 a. The didymous fruit, b. The involucrum beneath the 

 umbel, c. The involucellum, beneath the umbellet or par- 

 tial umbel. 



Fig. 2. — A separate flower with its 5 obcordate inflected petals. 

 a. A petal, b. A stamen. 



t The following, is the specific character of thisundescribed species. 

 American Coriander, with didymous fruit; umbel perfect, involucrum 

 general and partial many-leaved. Hab. (or locality). Found 

 in the prairies of Red River territory ; common. 



