VACCINIUM 



VAUCINIUM 



BOTANICAL CLASSIFICATION. In the following scheme 

 the species are separated on the basis of natural char- 

 acters. When two closely related forms occur over 

 wide range in latitude, however, the assigned dif- 

 ferences are liable to fail at some point. The key 

 will be found useful in determining herbarium speci- 



A. Ovary 4~5-loculed(rarely 8-10- 



loculed in V. Vitis-Idcea). 

 B. Stamens long-exserted. 



c. Filaments villous 5. erythrocarpon 



CC. filaments puberulent. 

 D. Stems very slender, 



creeping 1. Oxycoccus 



DJ>. Stems stouter, with as- 

 cending branches 2. macrocarpon 



BB. Stamens included. 



C. filaments glabrous or pu- 

 bescent. 

 D. Corolla commonly 4- 



lobed: stamens 8 21. uliginosum 



DD. Corolla commonly 5- 



lobed: stamens 10. 

 E. Plants dwarf, a foot or 



less high. 



F. Branchesnotangled.lQ. caespitosum 

 FF. Branches sharply 



niujled 9. Myrtillus 



EE. Plants taller, 1-12 ft. 



hiah. 

 F. Margins of leaves 



xharply serrulate.15. myrtilloides 

 FF. Man; ins of leaves 

 entire (except in 

 V. ovalifolium). 

 G. Length of Ivs. 1- 



2 inches 1C. ovalifolium 



GG. Length of Ivs. %- 



% inches 4. parvifolium 



CC. Filaments pilose. 



D. Twigs red. Here prob- 

 ably belongs 22. erythrinum 



DD. Twigs not red. 



E. Stamens 10: ovary 5- 



loculed. 



F. Branchlets pubes- 

 cent 23. ovatum 



FF. Bran chiefs gla- 

 brous 20. crassifolium 



EE. Stamens 8: ovary 4- 



loculed 3. Vitis-Idsea 



AA. Ovary 10-loculed (sometimes 



imperfectly so}. 



B. Anthers with 2 awns on the 

 back. 



C. Stamens included 24. arboreum 



cc. Stamens exserted 25. stamineurn 



BB. Anthers awnless. 



c. foliage evergreen, coria- 

 ceous. 

 D. Calyx -teeth roundish 



and very dense 6. nitidum 



DD. Calyx-teeth acute 7. Myrsinites 



CC. foliage deciduous (some- 

 times tardily so in south- 

 ern forms). 



D. Corolla cylindraceous . .17. virgatum 

 DD. Corolla short and usu- 

 ally broad. 



E. Branchlets hirsute. . .14. hirsutum 

 EE. Branchlets glabrous 

 or glaucous (except 

 in V. Canadense). 

 F. Lvs. glaucous and 

 pale beneath. 



a. fruit blue 8. vacillans 



GG. fruit black 12. nigrum 



FF. Lvs. strongly pubes- 

 cent both sides.. .13. Canadense 

 FFF. Lrs. glabrous, often 

 hairy on midrib 

 beneath. 



G. Margin of Ivs. 

 bristly -serru- 



l"ti' 11. Fenusylvanicum 



GG. Margins of Ivs. en- 

 tire or at most 

 ciliate. 

 H. Berry blue, 



glaucous 18. corymbosum 



HH. Berry black, 



not glaucous. 19. atrococcum 



HORTICULTURAL CLASSIFICATION. The following key 

 to the more commonly known species is based upon 

 horticultural or garden characters : 



A. Species cultivated chiefly for 



fruit. 

 B. Color of fruit red. 



C. Stems slender, trailing: 

 Ivs. evergreen. 



D. Apex of leaves acute 1. Oxy coccus 



DD. Apex of leaves obtuse or 



refuse 2. macrocarpon 



cc. Stems stouterthough creep- 

 ing: branches erect, 



tufted 3. VitiB-Idaea 



CCC. Stems erect, much taller, 



2-10 ft. 



D. Lvs. small, %-% in. long. 4. parvifolium 

 DD. Lvs. larger, lY^-S in. 



long 5. erythrocarpon 



BB. Color of fruit blue or black. 



c. Plant low, %-S ft. high. 



D. Foliage evergreen. 



E. Lvs. small, %-% in. 



long C. nitidum 



EE. Lvs. larger, %-l in.. 7. Myrsinites 

 DD. Foliage deciduous. 



E. Surface of I vs. gla- 

 brous. 



F. Lvs. pale beneath, 

 not shining above. 

 (See also No. IS. 

 Here might be 

 sought V. corym- 

 bosum, var. palli- 

 dum,No.l8.) ,v vacillans 



FF. Lvs. not paler be- 

 neath, shining, at 

 least above. (Ex- 

 ceptions : No. It 

 always paler be- 

 neath; No. 11 

 rarely paler be- 

 neath.) 

 G. Fls. solitary in 



the axils. 

 H. Branches 



sharply an- 

 gled 9. MyrtillM 



HH. Branches not 



angled 10. caespitosum 



GG. fls. in fascicles 



or short racemes. 



H. '/'//< //.. not 



paler beneath. 11. Pennsylvanicum 

 HH. The Ivs. paler 



beneath 12. nigrum 



EE. Surface of the Ivs. 



hairy. 



F. Ovary and fr. glau- 

 cous 1:1. Canadente 



FF. Ovary and fr. h i r- 



sute 14. hirsutum 



cc. Plant taller, S-lt ft 



spreading. 

 D. Fls. solitary in axils. 



X. Lvs. sharply serrate .15. myrtilloides 

 EE. Lvs. entire or slightly 



serrulate 16. ovalilolium 



PD. Fls. in racemes or co- 



rymbs. 

 E. Racemes elongated on 



naked branches.... 17. virgatum 



