=Dwarf Mistletoe, Arceuthobium pusillum.=

ARISTOLOCHIACEAE, the Birthwort Family

Flowers greenish-brown or reddish-brown, at or near the ground, with
inferior 6-celled ovary.

1a. Leaves alternate, on the stem; flowers on a basal scaly branch (1-4
dm. high; summer) =Virginia Snakeroot, Aristolochia serpentaria.=

1b. Leaves a single basal pair, bearing 1 short-stalked flower between
them (spring) (Wild Ginger) --2.

2a. Lobes of the perianth ending in a tubular portion 5-8 mm. long
=Wild Ginger, Asarum canadense.=

2b. Lobes of the perianth ending in a tubular portion over 1 cm.
long =Wild Ginger, Asarum canadense var. acuminatum.=

2c. Lobes of the perianth triangular, not tubular at the end
=Wild Ginger, Asarum canadense var. reflexum.=

POLYGONACEAE, the Buckwheat Family

Herbs with alternate entire leaves, stipules surrounding the stem above
the base of each leaf, and small green, white or pink flowers without
petals.

1a. Erect or ascending or prostrate or floating plants --2.

1b. Scrambling or climbing plants, clinging by sharp recurved prickles
on the 4-angled stems (flowers greenish or pink, summer)
(Tear-thumb) --32.

1c. Twining vines (flowers white or greenish, summer) --33.

2a. Sepals 6, the 3 inner ones enlarging in fruit and surrounding
the achenes; flowers in panicles --3.

2b. Sepals 4 or 5 (occasional flowers may be found with 6 sepals,
but the flowers are not in panicles) (summer) --13.

3a. Leaves arrow-shape or halberd-shape, with 2 basal lobes (Sorrel)
--4.

3b. Leaves without basal lobes (Dock) --5.

4a. Leaves halberd-shape, the basal lobes directed sidewise
=Red Sorrel, Rumex acetosella.=

4b. Leaves arrow-shape, the basal lobes directed backward
=Green Sorrel, Rumex acetosa.=

5a. The projecting wings of the fruiting calyx (known as valves) with
sharp slender teeth =Bitter Dock, Rumex obtusifolius.=

5b. Valves entire or finely dentate, but without sharp slender teeth
--6.

6a. Pedicels straight, thickened toward the end, all regularly
deflexed, 3-4 times longer than the fruiting calyx
=Swamp Dock, Rumex verticillatus.=

6b. P