1. Petals united (Sympetalous, or Gamopetalous). 
2. Ovary superior. 
3. Corolla regular. 
4. Ovary 3-10 celled; anthers opening by terminal chinks or 
pores. Mostly shrubs— Ericaceae (Heath, Indian Pipe, 
Rhododendron, Trailing Arbutus, Cranberry, Blue- 
berry, Huckleberry). 
4. Ovary 1-celled, with free-central placenta. Stamens op- 
posite the petal-lobes, inserted on the tube— Primulaceae 
(Primrose, Shooting Star). 
4. Ovary 2-celled, with 2 (rarely more) ovules in each. 
Trees or shrubs, with 4-parted flowers— Oleaceae (Olive 
family) (Ash, Lilac, Privet). 
4. Ovary 1-celled, with 2 parietal placentae; many seeds. 
Leaves opposite and sessile— Gentianaceae (Gentian 
family). 
4. Ovaries 2, with a common stigma. Juice milky. 
5. Stamens not united— Apocynaceae (Dogbane, Myrtle). 
5. Stamens united; pollen in masses — Asclepiadaceae (Milk- 
weed family). 
4. Ovary 2-(or 3-) celled, with 2 ovules in each. Flowers 
mostly large and showy. Chiefly twining herbs, often 
with milky juice— Convolvulaceae (Morning Glory family) 
(Sweet Potato, Bindweed, Dodder). 
4. Ovary 3-celled, few— many seeded. Not twining — Pole- 
moniaceae (Phlox family). 
4. Ovary 1-celled, with 2 parietal placentae; 4-many seeds — 
Hydrophyllaceae (Waterleaf family). 
4. Ovary deeply 4-lobed— Boraginaceae (Borage family) (Hel- 
iotrope, Bluebells). 
4. Ovary 2-celled, many seeded. Fruit generally a berry — 
Solanaceae (Nightshade family) (Potato, Tomato, To- 
bacco, Egg-plant, Ground Cherry.) 
3. Corolla irregular, 2-lipped. Stamens 2 long, 2 short (didyn- 
amous), sometimes 2. 
4. Ovary 2-4-celled, not lobed — Verbenaceae (Verbena family) . 
4. Ovary deeply 4-lobed; stems square; leaves aromatic— 
Labiatae (Mint family). 
4. Ovary 2-celled, manyseeded; with axile placentae— Scroph- 
ulariaceae (Figwort family) (Snapdragon, Veronica, 
Foxglove). 
4. Ovary 2-celled, many seeded; with parietal placentae. 
Woody plants— Bignoniaceae (Trumpet flower, Catalpa). 
4. Ovary 2-celled; 4-12-seeded. Chiefly herbs, with opposite 
leaves— Acanthaceac (Acanthus family)- 
2. Ovary inferior. 
3. Tendril bearing herbs. Anthers commonly united— Cucurbit- 
aceae (Gourd, Muskmelon, Watermelon, Pumpkin). 
3. Without tendrils. 
4. Corolla regular. Leaves opposite or whorled, with 
stipules— Rubiaceae (Madder family) (Galium, Bluets, 
Coffee, Cinchona). 
4. Leaves opposite or perfoliate, without stipules. Mostly 
shrubs— Caprifoliaceae ( Honeysuckle family) (Viburnum, 
Elder), 
4. Flowers in heads; stamens distinct— Dipsacaceae (Teasel 
family) . 
