ROSACE^E 481 



mexicana are also trinerved. The primary leaves of the 

 first named are trifid, gradually increasing in size ; the 

 first two of the latter are oblong, succeeded by two other 

 oblong-elliptic ones. The cotyledons of Cotoneaster Simonsii 

 (fig. 325) agree strictly with the type. The leaves are ovate 

 and entire from the first to those of the adult. 



The second group includes a number of species belonging 

 to different genera, the cotyledons of which do not differ 

 materially from those of the last group except in being more 

 or less deeply emarginate. This type is well represented by 

 Spiraea opulifolia, having oblong-obovate, emarginate coty- 

 ledons. The first leaf is broadly ovate, succeeded by two 

 broader trifid ones ; all are palmately trinerved. The 

 cotyledons of Agrimonia viscidula are transversely oblong or 

 suborbicular, rather deeply emarginate, and cordate at the 

 base. The first leaf is cordate-orbicular, and the second one 

 pinnately trifoliolate. The cotyledons of Eucryphia cordifolia 

 are broadly-oblong, trinerved, but very slightly emarginate. 

 The first four leaves are oblong. Eosa moschata might 

 have been placed here, but its cotyledons are only slightly 

 emarginate. The same might be said of Eubus thyrsoi- 

 deus, which has broadly oblong or oval, minutely emar- 

 ginate, glandular-ciliate cotyledons. The first three or four 

 leaves are broadly ovate, and others show gradual evolution. 



The most distinct divergence from the type is that found 

 in a number of closely allied plants constituting the tribe 

 Poterieae, and therefore forming a very natural group. The 

 cotyledons are broadly oblong and short, or oblong-orbicular, 

 deeply notched or cordate at the base, slightly emarginate, 

 and petiolate. This type is well exemplified in Acaena myrio- 

 phylla (fig. 319). The first leaf is pinnately five-foliolate, and 

 the ultimate leaves pinnate, pinnatisect with linear or sub- 

 ulate acute segments. To this may be added A. ovalifolia, 

 Agrimonia Eupatoria, and Poterium Sanguisorba (fig. 321). 

 The latter shows numerous incurved, slender veins proceed- 

 ing from the midrib of the cotyledons. The two primary 

 leaves are trifoliolate, the ultimate ones imparipinnate with 

 numerous orbicular or shortly oblong, deeply toothed leaf- 

 lets. The basal notch is due to the cotyledons becoming 



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