VACCINIUM 



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- 

 mens. 



a. Ovarii 4-5-loculed(rarely 8-10- 

 loculed in V. Vitis-Idota). 

 b. Stamens long-exserted. 



c. Filaments villous 5. erythrocarpon 



CO. Filaments puberulent. 

 D. Stems very slender, 



creeping 1. Oxycoccus 



dd. Steins 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. BranchesnotangledAO. caespitosum 

 FF. Branches sharply 



angled '. 0. Myrtillus 



EE. Plants taller, 1-12 ft. 

 high. 

 F. Margins of leaves 



sharply serrulate.Vb. myrtilloides 

 ff. Margins of leaves 

 entire (except in 

 V. ovalifolium). 

 G. Length of Ivs. 1- 



2 inches 10. ovalifolium 



GG. Length of Ivs. %- 



% inches 4 parviiolium 



CC Filaments pilose. 



D. Twigs red. Here prob- 

 ably belongs 22. erythrinum 



DD. Twi<is not red. 



E. Stamens 10: ovary 5- 

 loculed. 

 f. Bronchitis pubes- 

 cent 23. ovatum 



ff. Br a n c h lets g la - 



brous 20. crassifolium 



ee. Stamens 8: ovary 4- 



loculed 3. Vitis-Idaea 



aa. Ovary 10-loculed (sometimes 

 imperfectly so). 

 B. Anthers with 2 awns on the 

 back. 



c. Stamens included 24. arboreum 



OC. Stamens erserted 25. stamineum 



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 insouth- 

 ern forms). 

 D. Corolla cyliudraceous . .17 '. virgatum 

 dd. Corolla short and usu- 

 ally broad. 

 e. Bin nrh lets hirsute. ..14. hirsutum 

 ee. Branch lets glabrous 

 or glaucous (except 

 in V. Canadense). 

 F. Lvs. glaucous and 

 pale beneath. 



a. Fruit blue 8. vacillans 



GG. Fruit black 12. nigTUui 



FF. Lvs. strongly pubes- 

 cent both sides.. A3. Canadense 

 FFF. Lvs. glabrous, often 

 hairy on midrib 

 beneath. 



VACCINIUM 



1891 



G. Ma rg i u of Irs. 

 bristly -serru- 

 late 11- Pennsylvanicum 



GG. Margins of Irs. en- 

 tire or at most 



cthatr. 



H. Berry b I ue, 



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: 

 lvs. evergreen. 



D. Apex of leaves acute 1. Oxycoccus 



DD. Apex of leaves obtuse or 



retuse 2. macrocarpon 



cc. Stems stouterthough creep- 

 ing: brandies erect, 



tufted 3. Vitis-Idaea 



CCC. Stems erect, much taller, 

 2-10 ft. 

 d. Lvs. small^/i-Yi in. long. 4. parvifolium 

 dd. Lvs. larger, l%-8 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 (">. 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. 12. 

 Here might be 

 sought V. corym- 

 bosum, var. palli- 

 dum, No. IS.) 8. vacillans 

 FF. Lvs. not paler be- 

 neath, shining, at 

 least above. (Ex- 

 ceptions : No. 12 

 always paler be- 

 neath; No. 11 

 rarely paler be- 

 neath.) 

 G. Fls. solitary in 

 the axils. 

 H. Branches 



sharply an- 

 gled !). Myrtillus 



HH. Branches not 



angled 10. caespitosum 



GG. Fls. in fascicles 



or short racemes. 



H. The lvs. not 



palerbeneuth.il. Pennsyl vanicum. 

 hh. The lvs. paler 



beneath 12. nigrum 



EE. Surface of the Ivs. 

 hairy. 

 F. Ovary and fr. glau- 

 cous 13. CanadenBe 



FF. Ovary and I r. hir- 

 sute 14. hirsutum 



cc. Plant taller, 8-12 ft 

 spreading . 

 D. Fls. solitary in axils. 



E. Lvs. sharply serrate. 15. myrtilloides 

 ee. Lvs. entire or slightly 



s, rr it lute 10. ovalifolium 



DD. Fls. in racemes or co- 

 rymbs. 

 E. Baceines elongated on 



naked branches 17. virgatum 



