2a. Roots several from each rounded plant =Duckweed, Spirodela polyrhiza.= 2b. Root single from each rounded plant =Duckweed, Lemna spp.= Three species are reported from Michigan, of which the commonest is Lemna minor. ERIOCAULACEAE, the Pipewort Family Bog or marsh herbs, with small flowers in heads terminating long slender scapes. One species in Michigan; leaves linear and basal; flower-stalk 5-15 cm. high; flower-heads whitish or lead-color =Pipewort, Eriocaulon articulatum.= XYRIDACEAE, the Yellow-eyed Grass Family Small herbs with basal leaves and erect flower-stalks bearing a head of perfect yellow flowers, in summer. 1a. Base of plant bulbous-thickened (3-6 dm. high) =Yellow-eyed Grass, Xyris flexuosa.= 1b. Base of plant not bulbous-thickened (1-3 dm. high) =Yellow-eyed Grass, Xyris montana.= COMMELINACEAE, the Spiderwort Family 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.= PONTEDERIACEAE, the Pickerel-weed Family 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.= JUNCACEAE, the Rush Family 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.=