1 Leaves alternate; monoecious herb or shrub.

..2 Herb, < 2 (-3) dm tall; leaves 1-4 cm long, glabrous; inflorescence a terminal panicle of cyme

1 Leaves opposite; dioecious shrubs.

....3 Aerial (epiphytic) shrubs, parasitic on tree trunks and branches; leaves either coriaceous and brittle when live, or minute and scale-like

....3 Terrestrial shrubs, parasitic via root connections; leaves herbaceous, flexible when live.

......4 Staminate flowers in terminal umbel-like dichasia; pistillate flowers (and fruits) solitary, terminal; clumped shrub to 4 m tall

......4 Staminate flowers in axillary umbels; pistillate flowers (and fruits) solitary, axillary; rhizomatous shrub to 1 m tall

1 Leaves evergreen. {add to 1a: Scaevola in GOODENIACEAE, Morella (inodora) in MYRICACEAE, Ternstroemia in PENTAPHYLACACEAE, Myrsine in PRIMULACEAE, Pyracantha in ROSACEAE, Dodonaea in SAPINDACEAE, Cestrum in SOLANACEAE, Thymelaea in THYMELAEACEAE, Conocarpus in COMBRETACEAE}

..2 Leaves 1-7 mm long, either acicular and spreading or ovate and appressed to the stems

..2 Leaves > 10 mm long.

....3 Leaves linear, > 15× as long as wide; [Monocots]

....3 Leaves broader, < 15× as long as wide; [Eudicots, Basal Angiosperms, or Monocots].

......4 Plant a creeping subshrub, < 1 dm tall

......4 Plant not creeping, > 3 dm tall.

........5 Inflorescence an involucrate head

........5 Inflorescence solitary (Illicium in ILLICIACEAE) or variously branched, spicate, racemose, or fascicled, not an involucrate head.

..........6 Carpels separate; fruit an aggregate; fresh foliage strongly fragrant; [Basal Angiosperms]

............ 7 Fruit an aggregate of woody follicles arranged in a whorl

............ 7 Fruit an aggregate of red to blackish berries, 4-6 mm long, each on a long stipe, giving the aggregate almost the appearance of an umbel

..........6 Carpels fused; fruit a berry, drupe, acorn (nut), capsule, or legume; fresh foliage not strongly fragrant; [Eudicots, Monocots, and Basal Angiosperms].

............ ..8 Ovary with 3 carpels; fruit a berry; “leaves” actually cladodes; [Monocots]

............ ..8 Ovary with 1, 2, 3, 4, or 5 carpels; fruit a berry, drupe, capsule, legume, or nut; leaves actually leaves; [Eudicots and Basal Angiosperms].

............ ....9 Leaves largely covered with silver and/or bronze lepidote scales and/or dense stellate hairs below (visible at 10× or higher magnification), giving the lower leaf surface a slightly shiny to almost metallic appearance. {add Lyonia ferruginea and L. fruticosa in ERICACEAE; add Loropetalum in HAMAMELIDACEAE}

............ ......10 Petals present, conspicuous, connate, white, the corolla rotate; fruit a berry with several seeds; fresh foliage with a strong, tar-like odor

............ ......10 Petals absent or inconspicuous, greenish and separate if present (note that the calyx is petaloid and white or yellowish in Elaeagnus of ELAEAGNACEAE); fruit a dry capsule with 3 seeds, or a drupe with a single seed; fresh foliage lacking a strong odor.

............ ........11 Perianth 4-merous; petals absent; petaloid sepals white to cream, fused and salverform; carpel 1; fruit a fleshy, red drupe, with a single seed

............ ........11 Perianth 5-merous; petals green and separate, or absent; sepals greenish, separate; carpels 3; fruit a 3-valved capsule with 3 seeds

............ ....9 Leaves with various vestiture (or glabrous), but not as above.

............ ..........12 Flowers in spikes, these solitary opposite leaves or in axillary umbels

............ ..........12 Flowers in other types of inflorescences, not spikes.

............ ............ 13 Leaves 1-foliolate on the upper stems, sometimes 3-foliolate below, or all reduced to phyllodial spines; flowers papilionaceous, bright yellow; fruit a legume; stems bright green

............ ............ 13 Leaves simple throughout; flowers either small, inconspicuous, tannish, borne in catkins (Quercus), or larger and urceolate, or with almost separate and spreading petals, white to pink or reddish-orange, in various terminal or axillary, branched inflorescences; fruit either a nut in a cupule (an acorn), or a (3-) 5-valved capsule, or a spherical berry or drupe; stems generally brown or tan (sometimes green).

............ ............ ..14 Flowers small, inconspicuous, tannish, borne in catkins; fruit a nut in a cupule (an acorn)

............ ............ ..14 Flowers white to pink or reddish-orange, either urceolate or tubular or with separate and spreading petals, in various terminal or axillary inflorescences, or solitary; fruit either a (3-) 5-valved capsule, or a spherical berry with 10+ seeds, or a 1-8 seeded dry or fleshy drupe.

............ ............ ....15 Flowers white to pink or reddish-orange, rotate or urceolate (the petals united at least basally), in various terminal or axillary inflorescences or solitary; fruit either a 2-5 valved capsule or a spherical berry with 10+ seeds.

............ ............ ......16 Flowers reddish-orange; corollas bearing post-staminal hairs (appearing as tufts of hair opposite each anther)

............ ............ ......16 Flowers white to pink; corollas without obvious tufts of hair opposite each anther.

............ ............ ........17 Leaves 1 per node or also paired (on one side of the stem) at some nodes (the leaves then uneven in size); inflorescences leaf-opposed; fruit a berry.

............ ............ ........17 Leaves 1 per node; inflorescences terminal or axillary, never leaf-opposed; fruit a valved capsule.

............ ............ ..........18 Seeds without fleshy aril or attachment; ovaries 5-10 carpellate; flowers urceolate; leaves serrate or entire

............ ............ ..........18 Seeds with fleshy aril or attachment; ovaries 2-4 carpellate; flowers rotate; leaves entire or very remotely serrulate.

............ ............ ............ 19 Flowers few, not showy, green to greenish-white, inflorescence not densely arranged (flowers also sometimes solitary); capsules not beaked; leaves not revolute or undulate

............ ............ ............ 19 Flowers numerous, showy, white; inflorescence densely arranged; capsules with short beak; leaf margins revolute or slightly undulate

............ ............ ....15 Flowers white, petals spreading, separate even at the base, in axillary fascicles or racemes; fruit either a fleshy drupe with 4-8 pyrenes, or a dry single-seeded drupe.

............ ............ ............ ..20 Shrub rhizomatous and colonial; fruit an ellipsoid drupe, 2-3 cm long

............ ............ ............ ..20 Shrub not rhizomatous; fruit either a fleshy or dry drupe, < 1 cm long.

............ ............ ............ ....21 Inflorescence an axillary fascicle or cluster; fruit a fleshy drupe with 4-8 pyrenes

............ ............ ............ ....21 Inflorescence an axillary raceme; fruit a dry drupe with 1 seed

1 Leaves deciduous. {add: Ditrysinia in EUPHORBIACEAE, Glochidion in PHYLLANTHACEAE, Phyllanthopsis in PHYLLANTHACEAE, Nierembergia in SOLANACEAE, Edgeworthia in THYMELAEACEAE, Ipomoea (I. carnea) in CONVOLVULACEAE; Swida (S. alternifolia) in CORNACEAE}

............ ............ ............ ......22 Inflorescence an involucrate head

............ ............ ............ ......22 Inflorescence branched, spicate, a catkin, or consisting of a solitary flower or axillary clusters or whorls, not an involucrate head.

............ ............ ............ ........23 Inflorescence a catkin; flowers unisexual; plants dioecious

............ ............ ............ ..........24 Leaves 3.5-6 cm wide

............ ............ ............ ..........24 Leaves < 3 cm wide

............ ............ ............ ........23 Inflorescence various, not a catkin; flowers bisexual; plants hermaphroditic.

............ ............ ............ ............ 25 Inflorescences axillary, solitary flowers

............ ............ ............ ............ ..26 Fruit a globose, spinose capsule bearing a longitudinal ridge across 1 or both faces, thus essentially resembling a spikey ball; perianth (4-)5-merous, consisting of 3 upper connate petaloid claws and two lower sessile petals; fresh plants without a strange musky odor; [Eudicots]

............ ............ ............ ............ ..26 Fruit an oblong berry, greenish-yellow when ripe, not bearing small spines; perianth 3-4-merous, without connate petaloid claws; fresh plants fragrant with a strange, musky odor; [Basal Angiosperms]

............ ............ ............ ............ 25 Inflorescence of 2 or more flowers; perianth 3-5-merous; fresh plants not musky-fragrant; fruits various, not as above.

............ ............ ............ ............ ....27 Flowers 3-merous; fruit fleshy, red or greenish-yellow at maturity; ovary superior; [Basal Angiosperms or Eudicots].

............ ............ ............ ............ ......28 Leaves elliptic or narrowly elliptic, broadest near the middle; fresh plants strongly fragrant with a citrus-like aroma; stems unarmed; fruit a drupe, with a single seed

............ ............ ............ ............ ......28 Leaves obovate or oblanceolate, broadest near the apex; stems armed with nodal spines; fresh plants not fragrant; fruit a berry, with several seeds.

............ ............ ............ ............ ....27 Flowers 4-5-merous; fruit fleshy or dry, black, blue, brown, tan, or red at maturity; ovary superior or inferior; [Eudicots].

............ ............ ............ ............ ........29 Fruit a 4-5-valved capsule with many seeds; inflorescence either terminal, a corymb or panicle, or an axillary whorl

............ ............ ............ ............ ........29 Fruit either a drupe or berry (indehiscent, and variously fleshy or dry) or a dry 3-valved capsule with 1 seed; inflorescence axillary (solitary, clusters, fascicles, or racemes), or in a terminal raceme (Pyrularia in SANTALACEAE).

............ ............ ............ ............ ..........30 Leaves largely covered with silver and/or bronze shiny lepidote scales below, giving the lower leaf surface an almost metallic appearance

............ ............ ............ ............ ..........30 Leaves with various vestiture, but not as above.

............ ............ ............ ............ ............ 31 Ovary inferior or half-inferior; inflorescence an axillary cluster or raceme, or a terminal raceme.

............ ............ ............ ............ ............ ..32 Fruit a spherical berry, with 10 or more seeds

............ ............ ............ ............ ............ ..32 Fruit an elongate drupe (definitely longer than thick), with 1 seed.

............ ............ ............ ............ ............ ....33 Fruit 6-10 mm long; inflorescence an axillary fascicle

............ ............ ............ ............ ............ 31 Ovary superior; inflorescence an axillary cluster or an axillary raceme (borne themselves in clusters).

............ ............ ............ ............ ............ ......34 Fruits elongate, 8-20 mm long.

............ ............ ............ ............ ............ ........35 Fruit a red or orange berry, 8-20 mm long; leaves usually on spur-shoots; [salty coastal areas, or exotics of disturbed situations]

............ ............ ............ ............ ............ ........35 Fruit a yellowish-green drupe, 12-15 mm long; leaves on main stems; [rich forests, mainly inland]

............ ............ ............ ............ ............ ......34 Fruits spherical, < 10 mm long.

............ ............ ............ ............ ............ ..........36 Inflorescence a narrowly cylindrical raceme, clustered several to many at the tip of the previous year’s wood and below the current season’s growth; fruit < 3 mm in diameter

............ ............ ............ ............ ............ ..........36 Inflorescence an axillary cluster; fruit > 4 mm in diameter

............ ............ ............ ............ ............ ............ 37 Fruit dry, opening by 3 valves, 1-seeded; leaf pubescence stellate

............ ............ ............ ............ ............ ............ 37 Fruit fleshy, with 4-8 seeds; leaf pubescence simple or absent.

............ ............ ............ ............ ............ ............ ..38 Fruit yellow to red, the pedicel 10-30 mm long; leaf venation pinnate, but irregular and reticulated

............ ............ ............ ............ ............ ............ ..38 Fruit dark red to black, the pedicel < 10 mm long; leaf venation very neatly pinnate, with the secondary veins nearly straight and parallel to one another