1 Plant an herb, subshrub, or sprawling shrub, not clonal by underground rhizomes (except Gaultheria procumbens and Epigaea repens), rarely > 3 dm tall; plants mycotrophic or hemi-mycotrophic (except Epigaea, Gaultheria, and Arctostaphylos).

  2 Plants without chlorophyll (fully mycotrophic); stems fleshy; leaves represented by bract-like scales, white or variously colored, but not green; pollen grains single; [subfamily Monotropoideae; tribe Monotropeae].

    3 Petals united; fruit nodding, a berry; flower and fruit several per stem

    3 Petals separate; fruit erect, a capsule; flower and fruit 1-several per stem.

      4 Flowers few to many, racemose; stem pubescent, at least in the inflorescence; plant yellow, orange, or red when fresh, aging or drying dark brown

      4 Flower solitary; stem glabrous; plant white (rarely pink or orange-yellow) when fresh, aging or drying black

  2 Plants with chlorophyll (hemi-mycotrophic or autotrophic); stems woody; leaves present and well-developed, green; pollen grains in tetrads (single in Orthilia).

        5 Herb with a rosette of ascending basal leaves; flowers scapose; [subfamily Monotropoideae; tribe Pyroleae].

          6 Style and filaments straight; filaments straight, the anthers closely surrounding the style; inflorescence distinctly secund (1-sided)

          6 Style and filaments strongly declined; filaments curved, the anthers not closely surrounding the style; inflorescence slightly or not at all secund (1-sided)

        5 Subshrub or sprawling shrub with cauline leaves; flowers axillary (except scapose in Chimaphila).

             7 Plant erect, the leaves clustered near the apex of the single stem.

               8 Leaves lanceolate or oblanceolate, normally 2-4× as long as wide (sometimes proportionately less narrow in stunted individuals; fruit a capsule, borne 1-several on an erect scape above the leaves [subfamily Monotropoideae; tribe Pyroleae]

               8 Leaves obovate, 1-2× as long as wide; fruit a red berry, borne on nodding axillary pedicels beneath the leaves; [subfamily Vaccinioideae; tribe Gaultherieae]

             7 Plant creeping or sprawling, leaves scattered along the stems.

                 9 Flowers solitary and axillary; fruit a white berry; [subfamily Vaccinioideae; tribe Gaultherieae]

                 9 Flowers in axillary or terminal spikes or racemes; fruit a fleshy loculicidal capsule or red drupe.

                   10 Leaves glabrous, 1-3 cm long, tapered to the base; corolla urceolate; calyx not subtended by large bracts; [subfamily Arbutoideae]

                   10 Leaves pilose (glabrate in age), 2-10 cm long, rounded or subcordate at the base; corolla salverform, the lobes spreading; calyx subtended by 2 large bracts; [subfamily Ericoideae; tribe Phyllodoceae]

1 Plant either a shrub or tree (> 3 dm tall), or a shrub 1-3 dm tall (rarely a woody needle-leaved subshrub 0.5-1 m and definitely and obviously clonal by underground rhizomes; plants not mycotrophic or hemi-mycotrophic.

                     11 Leaves ca. 1 mm wide, 3-12 mm long, appearing opposite, alternate, or whorled (the internodes very short, thus the leaves generally appearing whorled); petals absent; fruit a subglobose, 2-stoned drupe, 1-3 mm in diameter; branches often appearing in whorls of 3-7; [subfamily Ericoideae; tribe Empetreae]

                       12 Leaves 5-15 mm long; shrubs 5-25 dm tall; drupes yellow or reddish, 1.5-3 mm in diameter; [of SC southward]

                       12 Leaves 3-6 mm long; shrubs 1.5-6 dm tall; drupes gray, 1-1.5 mm in diameter; [of NJ northward]

                     11 Leaves either > 2 mm wide or < 5 mm long, mostly alternate or whorled; petals present; fruit not as above, mostly either a capsule or 10- or many-seeded berry; branches appearing alternate or whorled; [subfamily Vaccinioideae; tribe Vaccinieae].

                          13 Ovary inferior; fruit indehiscent, a fleshy berry; [blueberries and huckleberries].

                            14 Ovary 10 locular; seeds 10; leaves glandular-punctate, at least on the lower surface (except G. brachycera)

                            14 Ovary 4-5 locular; seeds numerous; leaves not glandular-punctate

                          13 Ovary superior; fruit dehiscent, a dry capsule; [other heaths].

                              15 Petals separate; fruit 2-7-locular; either a shrub to 1 m tall with ovate to oblong, evergreen leaves, 0.6-1.2 cm long, or a shrub to small tree 2-6 (-9) m tall with elliptic, deciduous leaves, 4-12 cm long, or a shrub 1-2.5 m tall, with elliptic to ovate, evergreen leaves 2-4 cm long; [subfamily Ericoideae; tribe Phyllodoceae].

                                16 Fruit 4-7-locular; shrub to small tree 1-6 (-9) m tall; leaves 2-12 cm long; petals 12-30 mm long.

                                  17 Fruit 7-locular; leaves evergreen 2-4 cm long; petals 20-30 mm long; shrub 1-2.5 m tall

                                  17 Fruit 4-5-locular; leaves deciduous, 4-12 cm long; petals 12-14 mm long; shrub to small tree 2-6 (-9) m tall

                              15 Petals fused for part or all their lengths; fruit (4-) 5-locular; shrub or tree with leaves of various shape, evergreen or deciduous, these either < 6 mm long, linear and whorled, or > 12 mm long.

                                    18 Leaves opposite or whorled, < 5 mm long, linear; [subfamily Ericoideae, tribe Ericeae]

                                       19 Leaves opposite, sessile, clasping at the base

                                       19 Leaves whorled (in 4s), petiolate

                                    18 Leaves alternate or whorled, > 20 mm long.

                                         20 Flowers 4-merous; fruits 4-locular; leaves with a series of fascicles of trichomes on the midrib below; [subfamily Ericoideae; tribe Rhodoreae]

                                         20 Flowers 5-merous; fruits 5-locular; leaves not as above.

                                           21 Leaves coriaceous, evergreen, shiny and dark green above.

                                             22 Leaves sharply and distinctly serrate.

                                               23 Pedicels slender, 7-10 mm long; filaments strongly curved just below the anthers; pith transversely diaphragmed; [subfamily Vaccinioideae; tribe Lyonieae]

                                               23 Pedicels stout, 2-6 mm long; filaments straight; pith solid; [subfamily Vaccinioideae; tribe Gaultherieae]

                                             22 Leaves entire, or obscurely and finely crenulate-serrulate.

                                                 24 Capsules elongate, > 2× as long as broad, 8-18 mm long; [subfamily Ericoideae; tribe Rhodoreae]

                                                 24 Capsules ovoid to globose or subglobose, about as long as broad, 5-8 mm long.

                                                    25 Leaves with a prominent vein running parallel to (and about 1 mm in from) the margin; [subfamily Vaccinioideae; tribe Lyonieae]

                                                    25 Leaves without a prominent marginal vein.

                                                      26 Corolla saucer-shaped, 10-30 mm across; leaves entire; [subfamily Ericoideae; tribe Phyllodoceae]

                                                      26 Corolla narrowly urceolate, 4-6 mm across; leaves finely crenulate-serrulate; [subfamily Vaccinioideae; tribe Lyonieae]

                                                        27 Flower stalks with 2 opposite or subopposite subulate bractlets a little below the calyx; leaves glabrous below or short-pubescent on the midvein

                                                        27 Flower stalks with 2 opposite or subopposite triangular bractlets near the base of the pedicel; leaf lower surface punctate with stalked red glands

                                           21 Leaves membranaceous or subcoriaceous, deciduous or evergreen, if subcoriaceous and evergreen, then not shiny and dark green above.

                                                          28 Capsules elongate, > 2× as long as broad, 7-23 mm long; [subfamily Ericoideae; tribe Rhodoreae]

                                                          28 Capsules ovoid to globose or subglobose, about as long as broad, or broader than long, 2-7 mm long.

                                                            29 Leaves (at least the larger) > 2.5 cm wide.

                                                              30 Pedicels with 2 bracteoles.

                                                                 31 Capsule broader than long; shrub; bracteoles just below the calyx; [subfamily Vaccinioideae; tribe Gaultherieae]

                                                                 31 Capsule longer than broad; tree; bracteoles generally near the middle of the pedicel; [subfamily Vaccinioideae; tribe Oxydendreae]

                                                              30 Pedicels without bracteoles.

                                                                   32 Leaves entire to minutely serrulate; capsule sutures pale and thickened; [subfamily Vaccinioideae; tribe Lyonieae]

                                                                   32 Leaves crenate; capsule sutures not thickened and pale; [subfamily Vaccinioideae; tribe Andromedeae]

                                                            29 Leaves < 2.5 cm wide.

                                                                     33 Leaves linear to narrowly lanceolate, 8× or more as long as wide. strongly revolute, strongly whitened beneath; [subfamily Vaccinioideae; tribe Andromedeae]

                                                                     33 Leaves broader, not revolute or slightly so, not strongly whitened below.

                                                                       34 Leaves whorled or alternate; corolla saucer-shaped, 10-20 mm across; [subfamily Ericoideae; tribe Phyllodoceae]

                                                                       34 Leaves alternate; corolla narrowly urceolate, 2-8 mm across.

                                                                         35 Pedicels with 2 bracteoles near the summit; [subfamily Vaccinioideae; tribe Gaultherieae]

                                                                         35 Pedicels with 2 bracteoles near the base; [subfamily Vaccinioideae; tribe Lyonieae]

1 Petals fused; stamens spring-loaded, the anthers initially in pockets of the corolla; fruit 5-locular.

  2 Leaves whorled or opposite; inflorescence either an axillary raceme or a terminal corymbiform raceme.

    3 Leaves opposite, 1-4 cm long, subsessile; inflorescence a terminal corymbiform raceme

    3 Leaves whorled in 3s (rarely opposite), 2-5 cm long, the petioles 4-12 mm long; inflorescence an axillary raceme.

      4 Calyx lobes glandular-canescent and with marginal stipitate glands; leaves glabrous beneath; bracts and bracteoles densely glandular; stomates 18 μ long and 13 μ wide, 15-24 per 0.2 square millimeter; shrub to 1 (-1.2) m tall; [of ne. NC northward]

      4 Calyx lobes canescent but lacking glands; leaves short puberulent beneath; bracts and bracteoles nearly glandless; stomates 13 μ long and 9 μ wide, 35-51 per 0.2 square millimeter; shrub to 2 m tall (though often much shorter when growing in burned situations); [of se. and sw. VA southward]

  2 Leaves alternate; inflorescence an axillary fascicle or a terminal panicle.

        5 Leaves 0.5-1.5 cm long, 2-8 mm wide; twigs densely persistently hispid; [of the Coastal Plain of s. SC southward]

        5 Leaves 2.5-12 cm long, 7-50 mm wide; twigs glabrous or puberulent (glabrescent in age); [collectively widespread in our area].

          6 Leaves deciduous, dull, and subcoriaceous, 1.5-3 cm wide; inflorescence a fascicle of 1-3 flowers, axillary to leaf scars near the tips of the previous year's growth; petiole 1-4 mm long; [of the Coastal Plain of NC and SC]

          6 Leaves evergreen, glossy, and coriaceous, (1) 3-5 cm wide; inflorescence a terminal panicle; petiole 7-45 mm long; [widespread]

1 Plants aerial and epiphytic, hemiparasitic shrubs (usually growing out of the branches of trees)

1 Plants terrestrial, autotrophic or hemiparasitic shrubs or subshrubs.

  2 Leaves succulent, nearly as thick as wide; [brackish to saline situations]

  2 Leaves herbaceous or leathery (succulent in Borrichia), much wider than thick; [various habitats].

    3 Creeping or short subshrubs, the stems primarily prostrate (< 2 dm tall), or spreading-ascending to decumbent and < 3 dm tall (MALPIGHIACEAE, in part; Galphimia primarily erect subshrubs to 1 m tall, of TX only in our area).

      4 Petals clawed, the bases noticeably thinned compared to the broader tips; fruit schizocarps, breaking into 2-3 nutlets or 1-seeded cocci; [in part, Aspicarpa and Galphimia]

      4 Petals not clawed, of relatively similar width from base to tip; fruit various, but never schizocarps of 2-3 nutlets or 1-seeded cocci.

        5 Well-developed leaves 4-6 per stem; inflorescence a head subtended by 4 large white bracts

        5 Well-developed leaves many per stem; inflorescence of individual flowers axillary in pairs or clusters or in terminal cymes.

          6 Flowers yellow; leaves with pellucid or dark punctate glands (use at least 10× magnification)

          6 Flowers white, pale pink, or deep pink; leaves lacking sessile, punctate glands.

             7 Leaves linear; flowers pale to deep pink, 5-merous

             7 Leaves orbicular or elliptic; flowers white to pale pink, 4-merous or 5-merous

               8 Leaves orbicular; flowers 4-merous; fruit a red berry

    3 Upright or scrambling shrubs, > 3 dm tall.

                 9 Scrambling shrubs, armed with recurved paired spines at the nodes (except Santalum, which can be a scrambling shrub and has red flowers producing drupe-like fruit bearing an apical circular rim).

                   10 Plants armed with recurved paired spines at the nodes; fruit ribbed, the ribs obviously glandular; petioles not 2-ribbed; flowers greenish-white to yellowish in color

                   10 Plants unarmed; fruit not ribbed, instead drupe-like and bearing a circular rim at the apex; petioles 2-ribbed; flowers red

                 9 Upright shrubs, unarmed.

                     11 Inflorescence a terminal head of many flowers.

                       12 Head spherical, lacking an involucre of conspicuous bracts or phyllaries

                       12 Head flattened, either subtended by 4 large white bracts or by an involucre with >5 green phyllaries.

                          13 Head subtended by 4 large white bracts; leaves with prominently parallel-arcing secondary veins; flowers 4-merous

                          13 Head subtended by an involucre of >5 green phyllaries; leaves with venation otherwise; flowers 5-merous

                     11 Inflorescence otherwise (if terminal, the flowers not arranged in heads), either of a solitary flower, or one of a wide variety of inflorescences with flowers attached at different points along branched or unbranched axes (e.g. axillary).

                            14 Inflorescence flat-topped (broader than long), terminal, a compound cyme or corymb.

                              15 Leaves distinctly 3-veined from the base, the 3 veins converging again at the leaf apex; [s. FL only in our area]

                              15 Leaves with prominently pinnate venation; [collectively widespread]

                                16 Leaves conspicuously glandular-punctate and aromatic; fruit a berry; ovary inferior; flowers with abundant stamens and a cup-shaped hypanthium; (partial; Mosiera, Myrcianthes, Syzygium).

                                16 Leaves not glandular-punctate and aromatic (only herbaceous Hypericum sometimes with black or transluscent leaf punctae, thus keyed instead in S1); flowers with 1-5 or 8-10 stamens; fruit not a berry, instead either a capsule (Hypericum), drupe (Cornus; Viburnum), follicle (APOCYNACEAE), or prominently ribbed and stipitate anthocarp (Pisonia).

                                  17 Fruit prominently ribbed (an anthocarp), the ribs with stipitate glands, the fruit thus usually sticky (this persisting on herbarium specimens)

                                  17 Fruit lacking prominent glandular ribs, the fruit not generally sticky.

                                    18 Fresh plants with white, milky juice; pistils 2, united only by the style and stigma; fruit a pair of linear or fusiform follicles, > 5-8× as long as thick, these variously shaped (terete, compressed, or prominently 3-angled)

                                    18 Fresh plants not exuding a white, milky latex (instead clear or not apparent); pistil 1 (or 2-5 in Hypericum); fruit various, but not of paired, linear follicles (see below).

                                       19 Flowers bright yellow; stamens many; leaves < 1.5 cm wide; fruit a capsule; leaves with pellucid or dark punctate glands (use at least 10× magnification)

                                       19 Flowers white or creamy; stamens 4-5; leaves > 1.5 cm wide; fruit a drupe; leaves lacking sessile, punctate glands.

                                         20 Petals 5; foliage with simple hairs

                                         20 Petals 4; foliage with T-shaped hairs

                            14 Inflorescence either terminal, axillary or leaf-opposed, if terminal elongate (not flat-topped) or flowers solitary; if axillary then variously arranged (sometimes also solitary in the axils).

                                           21 Carpels many (> 9), either separate or fused; stamens many; perianth segments either many and undifferentiated into calyx and corolla, maroon, brown, or yellow (in CALYCANTHACEAE), or differentiated into a fleshy and persistent calyx of 5-9 sepals, and a deciduous corolla of 5-9 red (or white) petals (Punica in LYTHRACEAE).

                                             22 Fruit a wrinkled, 3-7 cm long, brown to black, elliptical aggregate of nearly spherical, large achenes; flowers solitary in axils; perianth segments many and undifferentiated into calyx and corolla, maroon, brown, or yellowish; ovary superior; branches unarmed

                                             22 Fruit a leathery, 4-15 cm in diameter, reddish, spherical berry with obpyramidal seeds surrounded by a juicy sarcotesta (pomegranate); perianth differentiated, the sepals fleshy and persistent on the fruit, the petals deciduous, 5-9, bright red to white; ovary inferior; branches typically armed with axillary spines

                                           21 Carpels 1-5 (-6), fused; stamens either 1-5 or 8-10 (except 10+ in MYRTACEAE); perianth segments 4-5 or 8, variously colored; fruit a simple capsule, drupe, or berry (including berry-like fruit); flowers 2-many, in axillary or terminal inflorescences OR sometimes solitary (MYRTACEAE, SANTALACEAE, and THESIACEAE); [Eudicots].

                                               23 Ovary inferior (flowers epigynous); corolla either absent, radially symmetrical, OR bilaterally symmetrical; fruit either a berry or a 1-seeded drupe (a berry or apically dehiscent capsule in MYRTACEAE).

                                                 24 Leaves conspicuously glandular-punctate and aromatic, evergreen and usually coriaceous; fruit a berry or apically-dehiscent capsule; flowers with abundant stamens and a cup-shaped hypanthium.

                                                 24 Leaves not both conspicuously glandular-punctate nor aromatic, membranous and deciduous; fruit a drupe or berry; flowers with 1-5 or 8-10 stamens, with or without a cup-shaped hypanthium.

                                                    25 Flowers unisexual and plants dioecious; corolla absent; pistillate flowers solitary, staminate flowers in pedunculate umbels or cymes, either terminal or axillary; fruit a 1-seeded drupe; leaves acute to acuminate at the apex

                                                      26 Inflorescences terminal

                                                      26 Inflorescences axillary

                                                    25 Flowers bisexual and plants hermaphroditic; corolla present; flowers paired, terminal or axillary, or in axillary spikes; fruit a berry; leaves rounded, obtuse, to acute (or acuminate in Lonicera maackii) at the apex

                                               23 Ovary superior (flowers hypogynous); corolla primarily radially symmetrical (zygomorphic in Citharexylum in VERBENACEAE and MALPIGHIACEAE; absent in Forestiera in OLEACEAE); fruit either a 1-4-seeded drupe, or a many-seeded berry (or berry-like fruit), or a capsule.

                                                        27 Leaves with a conspicuous mix of silvery stellate hairs (upper) and rusty colored scales (lower); ovaries bearing rusty colored scales; flowers small, yellowish and inconspicuous; [nw. PA northward]

                                                        27 Leaves glabrous or nearly so, lacking a conspicuous mix of stellate hairs adaxially and rusty scales abaxially; ovaries not bearing rusty colored scales; flowers of various size and color.

                                                          28 Stamens 8-10, of 2 different lengths in each flower; petals separate, 4-5 (-7), pink purple, 10-15 mm long; stems strongly arching, rooting at the tips; [plants of flooded to saturated wetlands]

                                                          28 Stamens either (1-) 2 (-4), or 4-5, or 10, all of the same length; petals fused (separate in RHAMNACEAE and BUXACEAE, but then < 5 mm long and white or cream), white, bright-yellow, lilac, or pink; stems erect (or at least not arching and rooting at the tips); [plants of various habitats].

                                                            29 Petals separate, 4-5, white or cream; stamens 4-5.

                                                              30 Petals clawed (the bases much thinner than the broader tips); fruit a drupe; inflorescence a terminal raceme (Byrsonima) or axillary corymbs or umbels (Malpighia); [in part, Byrsonima and Malpighia; some vining species will grow shrub-like, but those keyed in J3; TX and FL only in our area]

                                                              30 Petals not clawed, the width similar throughout; fruit a drupe or capsule; inflorescence axillary and terminal.

                                                                 31 Fruit a loculicidal capsule, dehiscing into 3 valves; branches square in ×-section; leaves < 2 cm long; [exotic, cultivated and weakly established, of temperate areas]

                                                                 31 Fruit a drupe with 2-4 pyrenes; branches round or nearly so in ×-section; leaves > 2 cm long; [natives, of peninsular FL]

                                                            29 Petals fused (at least basally), 4-5, white, bright yellow, lilac, or pink; stamens either (1-) 2 (-4) or 10; fruit either a capsule or a 1-seeded drupe.

                                                                   32 Inflorescence a drooping axillary raceme (sometimes minutely so), flowers zygomorphic; fruit a drupe

                                                                   32 Inflorescence various, if a raceme then not conspicuously drooping, flowers actinomorphic; fruit a drupe or capsule.

                                                                     33 Perianth 5-merous; corolla pink; stamens 10; fruit a 5-locular capsule

                                                                     33 Perianth 4-merous; corolla white, bright yellow, or lilac; stamens (1-) 2 (-4); fruit either a 1-seeded drupe or a 2-locular capsule