ROSACEAE. — SORBUS 479 



Rhacheos interstitia 1-1.4 cm. longa; foliola minora (2.5-5 cm.: 0.8-1.3 cm.), 

 dentibus utrin-secus circiter 10-20, supra parce pilosa subtus glabra v. parco 

 pilosa; epidermis subtus pro parte laevis pro parte irregulariter striata. 

 Inflorescentia minor (2.5-6.5 cm. lata), initio parce fusco-villosa. Folia 

 plerumque 7-9-, raro ad 11-juga, cum petiolo l-2(-2.5) cm. longo 10-15(-18) 

 cm. longa 14. 5. Rehderiana. 



4. Group. 



Folia 4-5-iuga; rhachis exalata, interstitia 1.3-2 cm. longa; folia cum petiolo 

 2-4.5 cm. longo 10-18 cm. longa; foliola majora (3-5.5 cm.: 1.2-1.7 cm.), 

 glabra; epidermis subtus reticulato-striata, circa stomata obscure papillosa. 



Inflorescentia 12 cm. lata, glabra; carpidia 5 15. <S. aperta. 



Folia B-S-juga; rhachis vix v. angustissime alata, interstitia 0.5-1.3 cm. longa; 

 foliola minora (ad summum 4.2 cm. longa). 

 Foliola subtus glabra; epidermis subtus irregulariter striata epapillosa. In- 

 florescentia 9-11 cm. lata; carpidia 5, inde a placenta segregata. Folia cum 

 petiolo 2.5-3.5 cm. longo 10-16 cm. longa; interstitia 1-1.3 cm. longa; foliola 



2-4 cm. longa, 0.8-1.5 cm. lata 16. 5. laxiflora. 



Fohola subtus juxta costae basin albo-lanata; epidermis subtus circa stomata 

 V. ubique papillosa. Inflorescentia 2.5-5.5 cm. lata; carpidia 4 v. 5, semicon- 

 nata v. tola fere connata. Folia cum petiolo 1.5-2.8 cm. longo 7.5-15 cm. 

 longa; interstitia 0.5-1.3 cm. longa; foliola 2-4.2 cm, longa, 0.7-1.3 cm. lata. 



17. S. hupchensis. 



5. Group.i 



Epidermis foliolarum subtus ubique, rarissime nonnisi circa stomata, manifests 

 papillosa. 

 Flores baud manifeste glomerulati. 

 Folia 9-13-juga. Carpidia glabra, styli basi pubescentes. 



Stipula siccae; rhachis laxe villosa; foliola paullo majora (1.5-2.7 cm.: 

 0.5-1 cm.), pleraque tertia v. dimidia parte integra superne serrulata. 

 Inflorescentia parce subochraceo-villosa. FoUi rhachidis interstitia 0.6- 

 1 cm. longa; foliola subtus parce, in costa densius ochraceo-villosa. 

 Petala 5 mm. longa, medio limbo parce barbata. Carpidia 4 v. 5. 



18. S. Prattii. 

 Stipulae herbaceae parvae; rhachis glabra; foliola minora (1.3-2 cm.: 0.4- 

 0.7 cm.), basi tantum integra, argutius et paullo profundius serrata. 

 Inflorescentia fructifera glabra. Folii rhachidis interstitia 0.5-0.8 cm. 

 longa; foliola subtus saltem in costa f)arce albido-lanata v. tota facie 

 subochraceo-arachnoidea. Petala ignota. Carpidia 5 . .19. S. munda. 

 Foha 14-16-juga. Carjiidia 5, glabra; styli glabri. Folii rhachis glabra; in- 

 terstitia 0.5-1 cm. longa; foliola inde a basi sensim angustata (1.6-3.2 cm.: 

 0.5-0.8 cm.), pleraque ad v. ultra medium integra superne minutim serrulata, 

 subtus laxe secus costam densius subrufo-lanata. Inflorescentia glabra; 

 petala 3.5 mm. longa, glabra v. vix barbulata. Carpidia 5, glabra; styli 



glabri 20. (S. aestivalis. 



Flores in glomerulis parvis conferti, inflorescentia e glomerulis circiter 12-20 

 composita. Folia 11-14-juga; rhachis glabra; interstitia 0.4-0.6 cm. longa; 

 foliola (1.5-2.6 cm.: 0.4-0.8 cm.) circiter supra medium v. apice tantum 



^ To determine quickly the species of this group it is important to examine 

 the epidermis of the leaves with the microscope. 



