8 MINNESOTA STUDIES IN PLANT SCIENCE 



Subsection I. Rotundifoliatae. Leaves orbicular or reniform-cordate, 

 short and stout, except in one species where they are long and slender; 

 crenate, long-petioled ; carpels united beyond the gland; follicles erect, 

 greenish or purplish; beaks stout or slender; stigmas globose or somewhat 

 flattened. 



Subsection II. Ciineifoliatae. Leaves cuneate at the base, tapering to 

 short or elongate petiole-like bases, rounded and deeply incised-toothed at 

 apex ; carpels united merely at the base or to the height of the gland ; cap- 

 sules stout and thick, except in one species where they are elongated ; beaks 

 stigmas thick. 



Like the section Arcbisa this is one of the most interesting and most 

 clearly defined of the series. While the characters of the leaves in the 

 above described subsections are decidedly distinctive, other strong and unmis- 

 takable characters are to be found in the carpels, the gland, and the mature 

 capsules. The very young carpels are conical but soon develop into stout 

 bottle-shaped organs surrounded at the base by the fleshy, but not deep, 

 gland. 



Key to the Species of Section Hycatica 



I. Leaves orbicular or reniform-cordate, crenate Subsection I. Rotundifoliatae 



A. Inflorescence open 



a. Inflorescence elongate, paniculate-cymose 5". arguta 



b. Inflorescence short, cymose, delicate 5. aestivalis 



B. Inflorescence contracted or capitate 5". Nelsoniana 



II. Leaves cuneate at the base, deeply incised-toothed at apex 



Subsection II. Cuneifoliatae 



A. Inflorescence open, with slender branches, many-flowered S. Lyallii 



B. Inflorescence few-flowered, the peduncles stout 



a. Follicles elongate, contracted S. davurica 



b. Follicles stout, beaks short and thick 5". unalasckensis 



The species of the Rotundifoliatae are most readily recognized by the 

 characters of the inflorescence as described in the key, especially in the 

 case of Saxifraga arguta. In 6". aestivalis the inflorescence is very delicate, 

 in which respect it differs most obviously from S. Nelsoniana. The same 

 characters hold true in regard to the species of the Cuneifoliatae to distin- 

 guish S. Lyallii from the other members of the group, which do not differ 

 to any extent in their inflorescences. S. davurica and S. unalasckensis can 

 be distinguished from each other by the mature follicles, as characterized 

 in the key. 



The young carpels are very similar in the Rotundifoliatae, and those of 

 5. aestivalis and 5. Nelsoniana (Plate IV) are difficult to distinguish from 

 each other except that those of the latter are larger and stouter, with con- 

 siderably thicker beaks and stigmas. The gland of S. aestivalis is much 



