A Guide to Moist-Soil Wetland Plants of the Mississippi Alluvial Valley

Brodleaves

B R OA D LE AVES Pigweed Amaranthus spp. (Amaranthus hybridus, A. spinosus, A. tuberculatus, A. viridus) Native; some species invasive; AMARA, AMHY, AMSP, AMTU, AMVI; varies from FAC to FACU habits and habitat: Robust annuals occurring from uplands into drier wetland margins. Common in moist-soil wetlands during drought years or after summer disking. Prolific seed producers in summer and autumn. Mature plants can reach heights exceeding 8 ft. Distinguishing Characteristics seedling: Stem is round and green to purple, often without hairs. New leaves are narrow, green to reddish purple on the upper surface. First true leaves are alternate and oval, with small notches at the tip. stems and leaves: Stem is robust (sometimes reaching several inches in diameter), branching, often near base. Stems usually have hairs and appear reddish green. Leaves are alternate, oval, long blades that are wider in the middle compared to the base and tip, with wavy margins and hairs along the veins. flowers: Flowers appear in clusters along leafy spikes; each flower contains three to eight floral bracts. Flower clusters up to ¾ in. wide and 2 to 8 in. long. Smaller flowers may occur between the petiole (leaf stem) and stem. June to first autumn frost. fruit and seed: Fruit is small, yellow to brown, and splits down the middle to reveal a brown or black, shiny, flat, oval seed (∕₁₆ in. long). similar plants: Many of the Amaranthus spp. appear similar. Those listed here are the most common in moist-soil habitats in the Mississippi Alluvial Valley. 47 Amaranthaceae Plant with flowers Typical leaves Plant with flower clusters Mature seed clusters B R OA D LE AVES Beggarsticks, bidens, bearded beggarticks Bidens aristosa Native; rarely invasive; BIAR; FACW habits and habitat: Annual or short-lived perennial, occurring in floodplains, swamps, and lakes and ponds when dry or along margins. Common in early summer following rapid drawdown of water and soil disturbance. Sometimes invasive in early succession habitat but generally restricted to wetland margins. Distinguishing Characteristics seedling: First true leaves are oblong and oppositely arranged along the stem. stems and leaves: Stem is upright or trailing with the ends erect, slender, and square. Leaves are opposite, mostly with two or three fern-like leaflets (1 to 4 in. long); dark green veins are evident on the lower surface. flowers: Flowers are 1 to 2 in. long, flat-topped, and yellow, located at the tip of nearly leafless stem. Disk center of the flower is also yellow. Flower is surrounded by green outer bracts.August to October. fruit and seed: Thin, angled nutlets (½ to 1 in. long and less than ∕₁₆ in. wide), smooth and sparsely haired, start green and become brown with maturity, with barbed spikes at the tip that attach to clothing or fur (hence the common name beggarticks). similar plants: Several similar Bidens spp. (BIDEN) inhabit moist-soil areas. 49 Asteraceae Typical growth with flowers (September) and serrate leaves (inset) Young plants (August) Flower B R OA D LE AVES Fleabane Erigeron annuus, E. philadelphicus, E. strigosus, E. vernus Native; ERAN, ERPH, ERST3, ERVE; varies from OBL to FACU habits and habitat: Annual or perennial herbs reaching 1 to 2 ft. tall. Commonly occur in uplands, forest edges, ditches, clearings, right-ofways , marshes, and floodplains. Many Erigeron spp. are common in uplands. Distinguishing Characteristics seedling: Low-growing leaves egg- to spoon-shaped and usually toothed. stems and leaves: Branched stems with or without hairs. Leaves alternate, simple, narrow, and long; often slightly toothed. flowers: Numerous flowers are yellow to yellowish in the center, surrounded by ray-shaped whorled petals that are white, blue, pink, or purple. Number of flower varies by species. June to August. fruit and seed: Seed is a narrow nutlet often topped with bristly hairs. August to February. similar plants: Similar in appearance and habits with many species of aster (Symphyotrichum spp.; SYMPH4). 51 Asteraceae Typical growth (Erigeronphiladelphicus) Flowers (Erigeronphiladelphicus) Leaf B R OA D LE AVES Boneset, lateflowering thoroughwort Eupatorium serotinum Native; EUSE2; FAC habits and habitat: Perennial herb that often grows in clumps. Occurs in dry to wet sites and open areas. Present often as a single plant or in small colonies. Spreads by wind-dispersed seeds. Distinguishing Characteristics seedling: New leaves attached to a hairless stem. The first true leaves are opposite and are narrowly separated like the mature leaves. stems and leaves: Stem can be single or several, stiff erect to drooping...