Plants without leaves.
Parasitic on branches or stems of evergreens. =Loranthaceæ.=
Not parasitic on trees; roots coral-like. (_Corallorhiza_)
=Orchidaceæ.=
Plants with leaves.
_Leaves parallel-veined._
(A) Flowers small, collected on a spadix. =Araceæ.=
(B) Flowers not collected on a spadix.
*Flowers regular; corolla lobes 6; stamens 6.
(_a_) Leaves grass-like, mostly at the base.
Flowers white or greenish. =Melanthaceæ.=
Flowers pink. (_Allium_). =Liliaceæ.=
Flowers blue. (_Sisyrinchium_). =Iridaceæ.=
(_b_) Leaves not grass-like, mostly on the stem.
Flowers white or pink. =Convallariaceæ.=
Flowers green. =Melanthaceæ.=
Flowers yellow or orange. =Liliaceæ.=
Flowers red or wine-color. (_Kruhsea_.)
=Convallariaceæ.=
**Flowers irregular, frequently with broad or
inflated lip and spur. =Orchidaceæ.=
_Leaves not parallel-veined._
(A) Flowers small, in close heads surrounded by an involucre.
Flowers all alike, florets ligulate. =Cichoriaceæ.=
Flowers not alike, central ones tubular, marginal
usually with rays. =Carduaceæ.=
(B) Flowers in umbels at the ends of the stems or branches.
Umbels broad, flat or nearly so, flowers white, yellow,
or purple. =Apiaceæ.=
Umbels round.
Flowers greenish; leaves compound. =Araliaceæ.=
Flowers white or pink; leaves simple.
(_Eriogonum_.) =Polygonaceæ.=
(C) Flowers not in umbels.
*Flowers regular.
(_a_) Flowers with 2 sepals and 5 petals;
corolla pink. =Portulacaceæ.=
(_b_) Flowers with 3 sepals and 3 petals;
seeds triangular. =Polygonaceæ.=
(_c_) Flowers with 4 sepals and 4 petals.
Stem angular; leaves in whorls. =Rubiaceæ.=
Stem round; leaves not in whorls.
Stamens 6, erect. =Brassicaceæ.=
Stamens 8, spreading. =Onagraceæ.=
(_d_) Flowers with 5 sepals or petals, distinct.
†Stamens as many or twice as many as the
corolla lobes.
Stems swollen at the nodes. =Caryophyllaceæ.=
Stems not swollen at the nodes.
Stem leaves numerous, entire, thin;
flowers in terminal or axillary
clusters, white or greenish. =Santalaceæ.=
Leaves basal, entire; flowers solitary
on a 1-leaved scape. =Parnassiaceæ.=
Leaves mostly basal, lobed or cut;
flowers in a close spike or head. =Saxifragaceæ.=
Leaves and stems fleshy.
Follicles 2. =Saxifragaceæ.=
Follicles 4. =Crassulaceæ.=
Leaves numerous, stiff, awl-shaped;
stems low, tufted. =Saxifragaceæ.=
††Stamens more than twice as many as the corolla lobes.
§Leaves basal or mostly so.
Leaves evergreen, simple or lobed, flowers yellow
or white, solitary on naked scapes.
(_Dryas._) =Rosaceæ.=
Leaves not evergreen, simple, lobed, or much divided.
Smooth.
Stems erect or floating. =Ranunculaceæ.=
Stems creeping.
Flowers white or pink. =Rosaceæ.=
Flowers yellow. =Ranunculaceæ.=
Rough-hairy.
Flowers yellow or pink. =Rosaceæ.=
Flowers white, blue or purple.
=Ranunculaceæ.=
§§Leaves mostly on the stem.
Leaves finely cut; stems creeping; flowers
white. =Rosaceæ.=
Leaves entire.
Leaves bright green, black-dotted;
flowers yellow. =Hypericaceæ.=
Leaves glaucous, without black dots;
flowers blue. =Linaceæ.=
(_e_) Flowers with 5 sepals and 5 united petals
or lobes.
†Stamens 3; flowers small, in terminal
clusters. =Valerianaceæ.=
††Stamens 5.
Opposite to the corolla lobes.
=Primulaceæ.=
Alternate with the corolla lobes.
Stems smooth, leafy; corolla
campanulate.
Stem leaves broad; flowers pink.
=Apocynaceæ.=
Stem leaves narrow; flowers blue.
=Campanulaceæ.=
Stems rough-hairy.
Corolla salver-form; stamens included.
=Boraginaceæ.=
Corolla tubular; stamens exserted.
=Hydrophyllacæ.=
†††Stamens 10; flowers mostly in terminal
heads or singly. =Pyrolaceæ.=
**Flowers irregular.
(_a_) Leaves all entire and basal, forming rosettes;
flowers blue. =Lentibulariaceæ.=
(_b_) Leaves all heart-shaped; flowers blue, white
or yellow. =Violaceæ.=
(_c_) Leaves not heart-shaped, simple or much cut,
not pinnate.
Stems square; flowers in close verticels in
the axils of the leaves or in terminal
heads. =Menthaceæ.=
Stems round; flowers numerous in elongated
terminal leafy heads or few on slender
stems in the axils of the upper leaves.
=Scrophulariaceæ.=
(_d_) Leaves palmate; flowers blue in elongated spikes.
=Ranunculaceæ.=
(_e_) Leaves pinnately divided; flowers pea-like.
=Papilionaceæ.=
(_f_) Leaves compoundly lobed, not pinnate.
Stems low, spreading, flowers small in
dense terminal or axillary spikes.
=Papaveraceæ.=
Stems erect; flowers drooping in open
terminal heads, either showy and spurred
or not showy and without spurs; leaves
maiden-hair fern-like. =Ranunculaceæ.=