The Plants of Michigan / Simple Keys for the Identification of the Native Seed Plants of the State - Henry A. Gleason

Leafy-stemmed herbs; flowers with 3 sepals, 3 petals, and 6 stamens, lasting but a single day; petals blue.

1a. Stamens 6; petals all equal (Spiderwort) [— 2.]
1b. Perfect stamens 3, sterile stamens 3; two of the petals larger than the third (3-6 dm. high; summer)	Day-flower, Commelina virginica.
2a. Sepals villous (3-10 dm. high; late spring)	Spiderwort, Tradescantia virginiana.
2b. Sepals glabrous, or with a tuft of hairs at the apex (4-10 dm. high; late spring)	Spiderwort, Tradescantia reflexa.

Aquatic herbs, with 6 rather conspicuous petals; flowers in summer.

1a. Flowers blue; leaves cordate-sagittate (3-10 dm. high)	Pickerel-weed, Pontederia cordata.
1b. Flowers yellow; leaves linear (submerged)	Mud Plantain, Heteranthera dubia.

Grass-like or rush-like plants, with inconspicuous greenish or brownish flowers, of 3 chaffy or scale-like sepals and as many similar petals.

1a. Leaf-sheaths closed; capsule 1-celled and 3-seeded; stem or leaves usually hairy at or near the base (1-4 dm. high). (Wood Rush) [— 2.]
1b. Leaf-sheaths open; capsule many-seeded; plants never hairy [— 4.]
2a. Flowers solitary at the ends of the branches of the umbel-like cluster (spring)	Wood Rush, Luzula saltuensis.
2b. Flowers in spikes or dense clusters [— 3.]
3a. Flower-cluster spike-like, nodding at the tip (summer)	Wood Rush, Luzula spicata.
3b. Flower-cluster umbel-like (spring)	Wood Rush, Luzula campestris var. multiflora.
4. The genus Juncus, or Rush, contains about 25 species in Michigan, blooming in summer or autumn. For their identification the Manuals should be consulted. One of the commonest species is Juncus effusus, growing in marshes, with erect leafless cylindrical stems, bearing a lateral cluster of flowers near the summit. Another common species is Juncus tenuis, with slender stems and linear leaves, growing in hard ground, especially in woodland paths.