Opposite & Whorled Leaved Forbs
Species in this group are biennial or perennial forbs with opposite or whorled leaves. Species can be differentiated based on overall plant size; leaf size and shape; and flower size, shape, and color.
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Resource Table
| Classification | Common Name | Other Common Names | Scientific Name | Other Scientific Names | Resources | Videos | Weed ID slides ppt (AGR 375) | National Distribution Map | Look-Alike Species |
|---|---|---|---|---|---|---|---|---|---|
| Restricted | Field scabiosa | blue buttons | Knautia arvensis | Link | Knautia arvensis | National Map | |||
| Restricted | Hemp nettle | Brittlestem hemp nettle | Galeopsis tetrahit | Link | Galeopsis tetrahit | National Map | |||
| Restricted | Common teasel | Dipsacus fullonum | Dipsacus sylvestris | UWEX Factsheet Link | Video | Dipsacus spp. | National Map | ||
| Restricted | Cut-leaved teasel | Dipsacus laciniatus | UWEX Factsheet Link | Dipsacus spp. | National Map | ||||
| Restricted | Garden yellow loosestrife | Lysimachia vulgaris | Link 1 Link 2 | Lysimachia vulgaris | National Map | ||||
| Restricted | Garden valerian | Garden heliotrope | Valeriana officinalis | Link | Valeriana officinalis | National Map | |||
| Prohibited/Restricted | Hairy willow herb | Epilobium hirsutum | Link | Epilobium hirsutum | National Map | ||||
| Prohibited | Japanese chaff flower | Achyranthes japonica | Link | Achyranthes japonica | National Map | ||||
| Restricted | Moneywort | Creeping Jenny | Lysimachia nummularia | Link 1 Link 2 | Lysimachia nummularia | National Map | |||
| Prohibited | Policeman's helmet | Impatiens glandulifera | Link 1 Link 2 | Impatiens glandulifera | National Map | ||||
| Restricted or Prohibited | - purple loosestrife (R) - wanded loosestrife (P) | Lythrum salicaria Lythrum virgatum | UWEX Factsheet Link 1 Link 2 | Lythrum salicaria | National Map | ||||
| Restricted | White bedstraw | Smooth bedstraw | Galium mollugo | Link 1 | Video | Galium mollugo | National Map |
Species Summary Table
| Scientific Name | Common Name | Leaves | Flowers | Fruits | Leaf Division | Flower Color |
|---|---|---|---|---|---|---|
| Achyranthes japonica | Japanese chaff flower | Opposite, oval to elliptic, toothless leaves with wavy edges | Tight clusters of spikes with tiny flowers with no petals; bottle-brush appearance; late summer | Small fruits lay flat against spikes; pair of bracts | Simple | Green |
| Dipsacus fullonum | Common teasel | Opposite, oblong, prickly, unlobed, join in cup around stem; up to 1 ½’ long | Egg-shaped spiky flowerhead with tiny purple flowers; bracts from base longer than flowerhead; June – Oct. | Tiny seeds form in spiky flowerhead | Simple | Pink |
| Dipsacus laciniatus | Cut-leaved teasel | Opposite, oblong, prickly, lobed, join in cup around stem; up to 1 ½’ long | Egg-shaped spiky flowerhead with tiny white flowers; bracts from base shorter than flowerhead; July - Sept. | Tiny seeds form in spiky flowerhead | Simple, lobed | White |
| Epilobium hirsutum | Hairy willow herb | Opposite, stalkless 2-5” long lance- shaped leaves with sharply toothed edges, prominent central vein | ¾” deep pink flowers with 4 notched petals arise from leaf axils; July – Aug. | 2-3” long tubular capsule of small, flattened seeds with hairy tufts | Simple | Purple |
| Galeopsis tetrahit | Hemp nettle | Opposite, 2 ½” long, hairy, egg- shaped, pointed tip, serrated edges | Whorls of 2-6 flowers at top of plant; pink to purple ¾” tubular flowers with broad upper lip and 3-parted lower lip; June – Sept. | Each flower matures to dark-brown fruit with 4 seeds | Simple | Pink to white |
| Galium mollugo | White bedstraw | Whorls of 6-8 oblong 3/8 – 1” long leaves; sharp point at tip; hairless, smooth, with rough edges | Branching clusters of ¼” creamy to greenish- white 4-petaled flowers; June – Sept. | Smooth, 1mm long fruit splits to 2 seeds | Simple | White |
| Impatiens glandulifera | Policeman’s helmet | Opposite or whorled, lance-oval shaped, toothed, 6” leaves with pointed tip | 5-parted white to pink to purple, spurred flowers arise from leaf axils; June – Oct. | Seed pods ~1” long | Simple | Pink |
| Knautia arvensis | Field scabiosa / blue buttons | Opposite, basal, 3-8” long, coarsely toothed or divided; densely hairy; smaller at top of stem | 1-1 ½” dome-shaped flowerheads with tiny 4-lobed pink to lilac flowers; 2 layers of leaf-like bracts with white hairs on edges; June – Sept. | Dome-shaped seed head with ¼” hairy, angular seeds | Simple, lobed | Pink to lilac |
| Lysimachia nummularia | Moneywort / creeping Jenny | Opposite, round, shiny, evergreen, ¾ - 1”, toothless | ¾” cup-like, 5-petaled yellow flowers in leaf axils; June – Aug. | Capsules with 1-5 small seeds | Simple | Yellow |
| Lysimachia vulgaris | Garden yellow loosestrife | Opposite or whorled, lance to oval leaves 2 ¾ - 4 ¾” long, ½ - 1 ½” wide; small black or orange glands; softly hairy below | Cluster of 5-petaled ½ - ¾” yellow flowers at end of stalk; June – Sept. | Dry egg-shaped capsules | Simple | Yellow |
| Lythrum salicaria | Purple loosestrife | Opposite or whorled, up to 4” long, 1” wide, toothless, pointed tip | Spikes densely packed with 5-7 petaled pinkish-purplish ½ - ¾” flowers; petals with wrinkled texture; July – Sept. | Flowers develop to purplish-brown seed pods | Simple | Purple |
| Valeriana officinalis | Garden valerian | Opposite, up to 8”, compound with 7-12 pairs of lance-shaped toothed leaflets | 4” flat to round clusters of pinkish-white ¼” flowers with 5 lobes; July – Oct. | Flowers develop to 1/8” brown seed with feathery hairs | Pinnately compound | White |