Honeyvine is common in Ohio but often mistaken for other vining plants such as various members of the bindweed/morning glory family, Convolvulaceae. But oleander aphids don’t feed on bindweeds or morning glories.
The seed pods should have been the identifying feature. However, as with many of my plant ID challenges, a plant pest provided a helpful clue to both the true identity of the honeyvine milkweed as well as the taxonomy of this native plant. Sadly, I still rely heavily on what’s eating a plant rather than the plant’s features to make a plant identification.
A Jekyll and Hyde Native Plant
One possible limiting factor in the unchecked spread of honeyvine is its soil requirements. Plants do best in fertile, moist soil. I’ve most often found honeyvine growing along lake or stream banks as well as in woods with consistently wet soils.
The flowers, seed pods, and of course the appearance of oleander aphids are solid telltale features separating honeyvine milkweed from members of the Convolvulaceae family. Members of the morning glory family sport showy bell-shaped flowers. Honeyvine milkweed has small white flowers that grow in clusters.
Honeyvine milkweed can arise from roots or seeds; it’s a prolific seed producer. Once seeds germinate, the plants quickly produce deep vertical taproots along with fibrous lateral roots. Both will easily break off if plants are pulled. A saying that I first heard from Bill Fountain (University of Kentucky, Horticulture) applies to this management problem: “if you pull the plants, all of its relatives show up for the funeral.”
Wind spreads seed from gardens, roadsides, orchards, hedges, plantations, vacant and industrial land.
Intact and disturbed forest and margins, tracks, coastline, cliffs, shrublands, mangroves, inshore and offshore islands, almost any frost-free habitat.
Rampant, evergreen vine (<10 m tall) with smelly, milky sap and twining flexible stems that are covered in down and woody near the base. Dark green leaves (3-12 x 2-6 cm) are hairless and dull on the top, greyish-downy underneath, and opposite on the stems. Clusters of 2-4 bell-shaped white flowers (20-25 mm diameter Dec-May), occasionally with pink streaks, are followed by distinctive thick, leathery, pear-shaped choko-like pods (10 x 7 cm) containing kapok-like pulp, which splits open to disperse many black, thistledown-like seeds.
What damage does it do?
Poisonous, causes dermatitis, protect skin against contact with sap. Destroy ripe pods first to minimise seeding.
1. Pull up seedlings (all year round).
2. Stump swab (best in summer-autumn): a product containing 100g picloram+300g triclopyr/L (100ml/L) or a product containing 200g 2,4-D+100g dicamba/L (200ml/L) or dicamba 50g/L (400ml/L). Remove all pods and dispose of at refuse transfer station, burn or bury deeply. Leave remaining cut material on site to rot down.
3. Spray (summer-autumn): a product containing 100g picloram+300g triclopyr/L (30ml/10L) or a product containing 200g 2,4-D+100g dicamba/L (12ml/L) or dicamba 50g/L (24ml/L).
Choko fruit is similar but leaves are more grape-like.
Germinates in light wells or semi-shade inside established forest, often long distance from seed source, and smothers and kills plants up into the canopy, preventing the establishment of native plant species. Feeding parts of butterflies drinking from the flowers become gummed up, leading to eventual starvation and death.
Rapid growth to canopy, forming large, heavy, long-lived masses. Produces masses of viable seeds that can drift long distances on air currents. Tolerant of shade, very tolerant of drought or damp, wind, salt, many soil types, and damage, but is frost tender. Poisonous and irritant-inducing (not grazed).