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Cerastium
See list of 9 species in this genusCerastium velutinum was reported from New England by Morton (2005a) based on a collection from Franklin County, MA—29 May 1892, Churchill s.n. (MO!). However, the specimen, though vegetatively robust, has anthers, sepals, and petals too short for C. velutinum. The specimen is our native C. strictum. Reference: Morton (2005a).
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1a. Plants perennial, with sprawling stems that root at the nodes or with rhizomes and axillary shoots that produce overwintering leaves
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2a. Stems and leaf blades densely white-tomentose, the surfaces ± concealed by tomentum
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2b. Stems and leaf blades pubescent with villous hairs (rarely the stems subglabrous), the surfaces visible
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3a. Petals 5–7 mm long, ± equal in length to the sepals; axillary shoots usually lacking; eglandular or occasionally with stipitate glands confined to the inflorescence
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3b. Petals 7.5–15 mm long, ca. 2 times as long as the sepals [Fig. 557]; axillary clusters of leaves or short shoots produced on lower stem; plants stipitate-glandular in the inflorescence and often also on the upper portion of the stem
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4a. Petals 7.5–9 (–9.5) mm long; sepals 3.5–6 (–7) mm long; anthers 0.8–0.9 (–1.1) mm long; reproductive stems 5–20 (–30) cm tall; plants growing in pristine as well as human-disturbed habitats
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4b. Petals 10–15 mm long; sepals 5–8 mm long; anthers 0.9–1.2 (–1.5) mm long; reproductive stems (15–) 25–35 (–40) cm tall; plants mainly from human-disturbed habitats
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1b. Plants annual, usually from taproots, lacking stolons, rhizomes, and axillary shoots
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5a. Flowers usually 4-merous throughout (very rarely 5-merous); capsules usually dehiscing by 8 apical teeth (by 10 teeth in 5-merous flowers)
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5b. Flowers 5-merous, with 5 or 10 stamens; capsules dehiscing by 10 apical teeth
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6a. Sepals and often the bracts apically with long, forward-pointing, white, eglandular hairs that potrude beyond the apex
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6b. Sepals and bracts lacking elongate, eglandular hairs that protrude beyond the apex
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7a. Bracts of inflorescence herbaceous throughout, lacking a scarious margin; leaf blades (10–) 15–50 (–60) mm long; androecium with usually 10 stamens (often only 5 in apetalous forms)
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7b. Bracts of inflorescence with a translucent, scarious, distal margin and tip; leaf blades 5–18 mm long; androecium with usually 5 stamens
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8a. Veins of petals unbranched; petals shorter than the sepals, only slightly notched, the apical sinus up to 0.5 (–1) mm deep [Fig. 556]; bracts with a broad scarious margin and apex
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8b. Veins of petals branched; petals equaling or shortly surpassing the sepals, prominently notched, the apical sinus 1–1.5 mm deep; bracts with a narrow scarious margin and apex
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Each photo represents one species in this genus.