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Butterweed (Senecio glabellus)

• Family: Aster (Asteraceae)
• Flowering: April-June.
• Field Marks: This Senecio has all of its leaves pinnately divided into 3-13 segments.
• Habitat: Low woods, swamps, fallow fields.
• Habit: Annual herb with fibrous roots.
• Stems: Erect, usually smooth, sometimes branched, hollow, up to 3 feet tall.
• Leaves: Alternate, deeply pinnately divided into 3-13 segments, each segment usually toothed, smooth; the lower leaves on long stalks; the upper leaves on short stalks, or stalkless.
• Flowers: Many crowded into a head, with many heads per plant; each head up to 1 inch across, subtended by small, green bracts; the outer flowers yellow and ray-like; the inner flowers yellow and tubular, forming a disk.
• Sepals: 0.
• Petals: Some ray-like, yellow; others tubular, yellow, 5-lobed.
• Stamens: 5.
• Pistils: Ovary inferior.
• Fruits: Achenes smooth, with a tuft of white hairs at the top.