=Milkwort, Polygala verticillata.=

7b. Spike loosely flowered, 2-5 cm. long
=Milkwort, Polygala verticillata var. ambigua.=

EUPHORBIACEAE, the Spurge Family

Herbs, with alternate, opposite, or whorled leaves and usually milky
juice. Flowers small or minute and inconspicuous, without petals and
frequently without calyx. In our commoner species, several staminate
flowers, each consisting of a single stamen only, and one pistillate
flower, consisting of a single pedicelled 3-lobed ovary only, are
included within a 4-5-lobed involucre, which is sometimes colored and
resembles a calyx or corolla.

1a. Stem-leaves alternate; inflorescence axillary; flowers with calyx
and several stamens (3-8 dm. tall; flowers greenish or purplish;
summer) (Three-seeded Mercury) --2.

1b. Stem-leaves opposite, usually inequilateral at base; flowers as
described for the family; apparent flowers in axillary clusters
(summer and autumn) (Spurge) --3.

1c. Stem-leaves alternate; inflorescence a terminal umbel-like cluster,
with its branches subtended by opposite or whorled leaves; flowers
as described for the family (Spurge) --9.

2a. Leaves ovate or ovate-lanceolate; flower-clusters shorter than
the subtending bract
=Three-seeded Mercury, Acalypha virginica.=

2b. Leaves lanceolate to oblong; flower-clusters equaling or
exceeding the subtending bract
=Three-seeded Mercury, Acalypha gracilens.=

3a. Stem and foliage glabrous --4.

3b. Stem and foliage more or less pubescent (stems prostrate or
ascending, 1-4 dm. long) --7.

4a. Erect or ascending, usually without basal branches (2-4 dm.
tall) =Spurge, Euphorbia preslii.=

4b. Prostrate or spreading, branched from the base (stems 1-4 dm.
long) --5.

5a. Leaves entire; plants of the shores of the Great Lakes
=Spurge, Euphorbia polygonifolia.=

5b. Leaves serrulate --6.

6a. Leaves broadly oblong or obovate; seeds obscurely wrinkled
=Spurge, Euphorbia serpyllifolia.=

6b. Leaves narrowly oblong; seeds with prominent transverse ridges
=Spurge, Euphorbia glyptosperma.=

7a. Seeds black =Spurge,