NOTES ON POLLINATION. 57 



bees, like Megachiles, seem to come for pollen only. The anthers 

 of the flowers are exserted and dehisce upward, and, as is usual in 

 Labiatse, the stigmas mature later and slightly exceed the anthers. 



AuDiBERTiA INCANA, var. pilosa, Gray, is a very conspicuous 

 member of the mountain flora in August. The bright pink or 

 magenta calyces and bracts and the blue or violet corollas make a 

 striking combination of color that succeeds in attracting humming- 

 birds as well as bees. Only the largest bees and humming-birds 

 can get honey in a legitimate way, for the corolla tube is from six 

 to nine lines long. Xyllocopas seem to be frequent guests, and both 

 these bees and the birds must strike the anthers, which are exserted 

 from three to six lines and dehisce downward. The stigmas occupy 

 similar positions in older flowers. Smaller bees come occasionally 

 for pollen, but they would not often visit flowers with mature stig- 

 mas. Hive bees are often seen pilfering the honey through little 

 punctures of the corolla-tube just above the calyx. 



Scutellaria angustifolia, Pursh, grows in masses along streams 

 and is very assiduously visited by Anthophora urbana. Honey is 

 abundant when the flowers have not been recently visited, but the 

 bees pay many visits to depleted flowers. Since the flowers are 

 from nine lines to an inch long, the head of the bee must be thrust 

 well down the throat of the flower, and the bee's back is dusted with 

 pollen from the anthers which are included in the fold of the upper 

 lip. The stigmas are similarly situated. Since the clusters have 

 only from one to three flowers expanded at one time, much of the 

 pollination is of one plant with another. 



ERiofiONUM Baileyi, Wats., carpets considerable areas in August 

 and succeeds admirably in securing cross pollination. The nine 

 filaments erect themselves, a few at a time, and hold the pink 

 anthers with upward opening cells Avhere the pollen is sure to 

 adhere to visiting insects. The styles, which have been closely coiled 

 during dehiscence, now rise and occupy their central position. After 

 the pollination of the flowers the perianth persists, and by changing 

 to rose color adds much to the attractiveness of the flower clusters. 

 Honey is usually perceptible at the base of the perianth and the 

 plants are humming with bees of many sorts. Megachiles, Macro- 



