80 



Rhodora 



[April 



(where it meets the lobule) it is usually not dilated at all and may 

 even be slightly decurrent, the keel being often obsolete. The small 

 and narrow lobules, rounded or very bluntly pointed at the apex, are 

 attached by a line which is straight or only slightly arched, and the 

 inner edge is usually shorter than the outer, an unusual condition in 

 the genus Porclla. The leaf-cells average about 20 n in the mifldle of 



Figs. 1-13. PORELLA PINNAT.V L. 



1. Branch (of first order) bearing a female branch with a perianth, and also a sterile branch, 

 ventral view, X 15. 2-4. Bracts and bracteole from a single involucre. X 35. 5. A bract 

 from another involucre, X 35. 6-8. Bracts and bracteole from a third involucre, X 35. 

 9-11. Bracts and bracteole from a fourth involucre, X 35. 12. Cells from the base of a 

 bract (lobe), showing papillae, X 200. 13. Teeth from the mouth of an immature perianth, 

 X 200. Figs. 1-3 were drawn from a specimen collected at Columbus, Kentucky, by N. L. T. 

 Nelson 1497: Figs, tj-8, 12, 13 from a specimen collected at Granby, Connecticut, by G. E. 

 Nichols; Figs. 9-1 1 , from the type specimen of Madolheca microrhyncha in the Taylor herbarium. 



the lobe and show small but distinct trigones. In the inflexed por- 

 tion the marginal cells extend at right angles to the edge and form a 

 distinct border. The underleaves (Fig. 1) are slightly if at all de- 

 current, the line of attachment (as in the case of the lobules) being 

 straight or only slightly arched. 



