ORCHIDACE^ 



Plate 105: Isotria verticillata 

 1, base of lip, drawn to show the glands, one 

 on each side ( X 7|). 2, column, showing papil- 

 lose stigma and the anther in normal position 

 ( X 3). 3, a stellate trichome highly magnified, 

 usually abundant on the lip in fresh specimens, 

 but easily deciduous. 4, upper part of column 

 with the anther turned back and the mealy 

 pollen exposed. 5, pollen tetrad highly magni- 

 fied, found germinating in situ. 6, pollen tetrad 

 before germination, highly magnified. 7, label- 

 lum spread flat, dra^vn to show the lobulate 

 keel and lateral lobes ( x 2^). 8, pollen tetrad 

 before germination, highly magnified. 9, flower 

 bud invested by the verticil of leaves, drawn 

 natural size. 10, labellum seen from the side 

 ( X 2|). 11, flower and leaves, natural size, drawn 

 from a specimen collected near North Easton, 

 Massachusetts, in May 1920, upper sepal in 

 position characteristic of floral maturity. (In 

 younger stages of development the upper sepal 

 is bent sharply backward.) 



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