Heath Family

Vaccinium

1 Trailing stems, erect shoots (if present) borne on horizontal stems; leaves evergreen, glossy and dark green above, rarely exceeding 20mm
  in length [cranberries] .............................................................................................................................................................................. Key A
1 Erect shrubs, growth form various; leaves deciduous to semi-evergreen, dull to somewhat glossy and medium green above, generally
  exceeding 20mm in length.
  2 Twigs of the season abundantly covered with small bumps on the surface, visible without magnification); [blueberries] ............... Key B
  2 Twigs of the season smooth; [deerberries] ............................................................................................................................................ Key C

Key A – cranberries

1 Leaves elliptic, broadest near middle, (5-)7-10(-18)mm long, (2-)3-4(-5)mm wide; leaves blunt-rounded and non-involute; pedicels
  with 2 green, leaf-like bracts 1-2mm wide; berry 8-15mm in diameter ............................................................................... Large Cranberry

Key B – blueberries

Note: Hybrids and apparent local races in this section are frequent, and will key poorly. Hybrids are particularly frequent among the highbush blueberries.

1 Shrubs rhizomatous, forming clonal colonies, upright stems < 1 m tall (and often < 0.5m tall); ["lowbush blueberries"].
  2 Leaves sharply serrulate (each tooth with a small glandular tip), 20-32mm long, 6-16mm wide, green and shiny below (rarely glaucous),
   glabrous or nearly so ............................................................................................................................................ Late Lowbush Blueberry
  2 Leaves entire or obscurely serrulate (if obscurely serrulate then 30-50mm long and 13-25mm wide), either glaucous and glabrous (or
   nearly so) beneath, or green and densely pubescent beneath ............................................................................ Early Lowbush Blueberry
1 Shrubs crown-forming, single-stemmed or several-stemmed from base, upright stems generally > 1m tall (often 2-3m tall, and rarely
   to 7m); ["highbush blueberries"].
  3 Young twigs glabrous; leaf surfaces glabrous; leaf margins eciliate or ciliate.
   4 Leaves 3-6cm long, 1.5-2cm wide, margins not ciliate; corolla 4-6mm long ....................................................... New Jersey Blueberry
   4 Leaves 3-8cm long, 2-3cm wide, usually ciliate-margined, at least basally; corolla 5-10mm long ....................... Highbush Blueberry
  3 Young twigs puberulent, at least in lines; leaf surfaces more-or-less pubescent; leaf margins ciliate (rarely eciliate).
   5 Hairs of twigs and leaf surfaces whitish; leaves medium to pale green, not darkening on drying; berry blue, glaucous; twigs and bud
    scales flesh-colored to reddish; corolla 5-10mm long, usually not narrowed to tip; blooming May ...................... Highbush Blueberry
   5 Hairs of twigs and leaf surfaces dingy, brownish, or dark; leaves dark green, darkening on drying; berry black; twigs and bud scales
    brownish-green to black; corolla 5-8mm long, often narrowed to tip; blooming February-April .............. Black Highbush Blueberry

Key C – deerberries

1 Leaves green beneath (often slightly paler but not at all glaucous); stamens 5-8mm long ........................................................... Deerberry

Gaylussacia


1 Leaves slightly leathery, upper surface shining, dark green, 1.5-4cm long; bracts of inflorescence equal to or longer than pedicels (5-12mm
  long), persistent; sepals, pedicels, bracts and leaves stipitate-glandular and pubescent ............................................ Dwarf Huckleberry
1 Leaves membranaceous to slightly leathery, upper surface dull, yellow-green to medium-green, 2-10cm long; bracts of inflorescence
  shorter than pedicels, early deciduous; sepals, pedicels, bracts and leaves with sessile glands, pubescent or not pubescent.
  2 Leaves glandular on both surfaces; racemes 0.5-1.5cm long ....................................................................................... Black Huckleberry
  2 Leaves glandular on the lower surface only; racemes 1-5cm long .................................................................................. Tall Huckleberry