HEATH FAMILY ERICACEAE
Plants in the heath family prefer acid soil and are usually shrubs with showy, radially symmetrical flowers that are sometimes dish-shaped. There are usually 5 (rarely 4) petals that may be united or separate. The flowers are solitary or in clusters. The simple, alternate leaves are often evergreen.
HEMP FAMILY CANNABINACEAE
Rather coarse plants with palmately lobed, toothed leaves. The staminate (male) and pistillate (female) flowers are on separate plants. Common and Japanese hops are vines, with the female flowers in dense, cone-shaped clusters (hops).
HOLLY FAMILY AQUIFOLIACEAE
These shrubs or small trees have alternate, simple, toothed, leathery, often evergreen leaves. The very small flowers are solitary or in clusters and have 3-6 sepals, 4 or 5 petals. Male and female flowers are on separate plants.
HONEYSUCKLE FAMILY CAPRIFOLIACEAE
Members of this family are usually shrubs or vines. The flowers can be radially or bilaterally symmetrical and there are 5 small sepals and 5 petals, united at the base and trumpet-like or two-lipped. The opposite leaves may be simple or compound.
Snowberries, wiegelia, viburnums, honeysuckles and elderberries are examples.
HORSECHESTNUT FAMILY HIPPOCASTANACEAE
Trees with opposite, palmately compound leaves with 3-9 elliptic or lance-shaped, toothed leaflets. (Only this family has opposite palmately compound leaves.) The large showy flowers are in upright, branched clusters. The tubular calyx has 4-5 sepals and the corolla 4-5 unequal rounded petals. The fruit is a large, roundish capsule that is spiny in some species, and splits into 3 parts, exposing 1-3 large, shiny brown seeds with a gray scar at the base. The seeds are not edible
HORSETAIL FAMILY EQUISETACEAE
The horsetails are not "flowers" in the usual sense and are a small remnant of a once large family that contributed substantially to the formation of coal. Elongated cone-like heads bear sporangia, and the jointed stems have a toothed sheath at each joint. There are no true flowers.