VACCINIUM 



Botanical Classification. — In the following scheme 

 the species are separated on tlie 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. Ovary 4~5-loeuled{rarely 8-10- 

 lociiled in V. I'itis-Idaa). 



B. *y«iH,».s- l,ni,l-,:rx,rl,-<l. 



c. Fii.n„,,it.< rill, .11.1 5. erythrocarpon 



CC. /■■ihn,,, Ht< ,,„l.,r„h}(t. 



D. Sl,„is r.r// slind.'i: 



creijiiiiii 1. Oxycoccus 



DD. Stems .iloiiler, icith «.<- 



cenditig brandies 12. macrocarpon 



BB. Stamens inc'tiided. 



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.in. caespitosum 

 FF. Branches sharply 



angled ',). MyrtiUus 



EE. Plants taller, 1-12 ft. 



p. Margins of leaves 



sharply serriihite.l'). myrtilloides 

 FF. Margins of leaves 

 entire {except in 

 V.ovalifoliiim). 

 G. Length of Ivs. 1- 



Z inches IG. ovalifolium 



GO. Length of Ivs. %- 



H inches 4 parvifolium 



CO. Filaments pilose. 



D. Twigs red. Here prob- 

 ably belongs 22. erythrinum 



DD. Tirigs not red. 



E. Stamens 10: ovary 5- 

 loc tiled. 

 p. Branchlets pubes- 

 cent 23. ovatum 



FF. Branchlets gla- 

 brous 20. crassif olium 



EE. Stamens S: ovary 4- 



loculed 3. Vitifl-Idffia 



AA. Ovary 10-loculed {sotnetitnes 

 imperfecthi so). 

 B. Anthers with 2 awns on the 

 back. 



c. Stamens included 24, arboreum 



CC. Stamens exserted 25. stamineum 



BB. Anthers awnless. 



0. Foliage evergreen, coria- 



D. Calyx -teeth roundish 



and very dense 6. nitidum 



DD. Calyx-teeth acute 7. MyTsinites 



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). 

 P. Lvs. glaucous and 

 pale beneath. 



G. Fruit blue 8. vacillans 



GG. Fruit black 12. nigii-in 



FF. Lvs. strongly pubes- 

 cent both sides., .y.l. Canadense 

 PFF. Lvs. glabrous, often 

 hairy on midrib 

 beneath. 



VACCINIUM 1891 



Q. Margin of Irs. 

 bristly -serru- 

 late 11. Pennsylvanicum 



GG. Margins of lvs. en- 

 tire or at most 

 ciliate. 

 H. Berry blue, 



jf glaucous 18. corymbosum 



HH. Berry black, 



not glaucous. 19. atrococcum 

 HoETiccxTURAL 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. Ozycoccus 



DD. Apex of leaves obtuse or 



retuse 2. macrocarpon 



CC. Stems stouterthough creep- 

 ing: branches erect, 



tufted 3. Vitis-Idaea 



ccc. stems erect, much taller, 

 2-10 ft. 

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

 DD. Xa!S. larger, 1}4S in. 



long 5. erythrocarpon 



BB. Color of fruit blue or black. 



C. Plant low, yi-S ft. high. 



D. Foliage evergreen. 



E. Livs. small, Ji-K in. 



long 6. nitidum 



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

 DD. Foliage deciduous. 



E. Surface of Ivs.gla- 



p. Lvs. pale beneath, 

 not shining above. 

 {See also No. IS. 

 Here might be 

 sought V. corym- 

 bosum. var. palli- 

 dum. No. IS.) 8. vacillans 

 FF. Lvs. not pairr be- 

 neath, shining, at 

 least above. {Ex- 

 ceptions: No. 12 

 always paler be- 

 neath; No. 11 

 rarely paler be- 

 neath.) 

 a. Fls. solitary in 

 the axils. 



sharply an- 

 gled 9. MyrtilluB 



HH. Branches no t 



angled 10. caBspitosum 



GG. Fls. in fascicles 



orshortracemes. 



H. The lvs. not 



palerbeneath.il. Pennsylvanicum 

 HH. 27je lvs. paler 



beneath 12. nigrum 



EE. Surface of the lvs. 

 hairy. 

 F. Ovary and fr. glau- 

 cous 13. Canadense 



FF. Ovary and fr. hir- 

 sute 14. hirsutum 



CC. Plant taller, S-12 ft 

 spreading. 

 D. Fls. solitary in axils. 



E. Lvs. sharply serrate.l5. myrtilloides 

 EE. Lvs . entire or slightly 



serrulate IG. ovalifolium 



DD. Fls. in racemes or co- 

 rymbs. 

 E. Bacemes elongated on 



naked branches 17. virgatum 



