Jetbead (Spring 2023)
Hello Invader Detectives!
Have you seen a plant with white flowers and bright green leaves? Sounds like dogwood, blackberry, even honeysuckle, right? Today’s post is highlighted on black jetbead (Rhodotypos scandens). Spring has sprung and the shrubby jetbead is now in bloom.
Jetbead by huntingbon
Since jetbead is currently flowering, it’ll make it easy to spot. Flowering typically occurs from late April through early May (Midwest Invasive Species Information Network, n.a.). The flowers have 4 white, wide petals with white to pale yellow stamens and are terminal, meaning they occur at the end of a branch.
Jetbead has bright green leaves that are double serrated and in opposite arrangement. The leaves have a wide, round base and a narrow tip. The backside of the leaf is somewhat hairy and doesn’t change in color. This shrub is deciduous, so don’t expect to see any leaves in autumn (MISIN, n.a.). Having no leaves doesn’t mean that Rhodotypos will be hard to identify in the winter; four chestnut-colored fruits will be emerge from the flower and mature in the fall to be shiny, black, and bead-shaped (MISIN, n.a.). These fruits will persist through the winter on the shrub’s arching stems.
Jetbead by huntingbon
Jetbead is a very recognizable plant; native flowering dogwood (Cornus florida) was the only plant that could potentially be confused with jetbead. The most notable difference is Cornus is a tree while Rhodotypos is a shrub. Yes, there can be fine line between shrub and tree, but jetbead reaches to 6ft while dogwood reaches 30-40ft at maturity (Swearingen & Fulton, 2022; University of Kentucky, n.a.).
With that said, there are many similarities where they may be confused, especially on iNaturalist where it might be difficult to identify some photos of plants. Flowering dogwood and jetbead follow similar phenology: flowers late April to early May, fruits mature in fall, and are deciduous. They both have 4-petaled white flowers, similar-shaped leaves. The white petals of dogwood flowers are in fact bracts, not petals; the true flowers are yellow to green clustered in the center. Dogwood fruits will cluster but are red when mature.
Left: Flowering dogwood by kemper, iNaturlist; Right: Dogwood leaves and flowers by cairn
Dogwood leaves can be bright green like jet bead, but dogwood leaves are entire and may look glossy; the underside is hairless.
How to look for Jetbead
Jetbead is easily identifiable due to its distinct leaves, flowers, and fruits. Alex was able to see it from across the road while we were driving by the National Zoo. I’ve seen it countlessly during hikes along the trails, especially where water is close by. According to Rawlins et al. (2018) and Swearingen & Fulton (2022), Rhodotypos does best in sunny areas with moist, rich soils, but can adapt to disturbed and polluted areas, shade, and different types of soils and pH. Here in the mid-Atlantic, you can find it in “forest interiors” (Swearingen & Fulton, 2022).
Tips for making a good observation
Take photographs that show:
the landscape around the plant – this shows the context and offers a clue to the scale of the
infestation
if they are flowering, photograph a whole plant including flowers and leaves
if they aren’t flowering yet, photograph a whole, typical, undamaged leaf.
with jetbead, you should be able to find some fruits as well.
Make comments that:
are explicit about the issue of intentional plant vs weed vs escaped (You’d be surprised but
some parks include intentionally planted alien plants which are now invasive – life is
complicated!)
give a rough estimate of the number of patches and the area covered
any other comments you think might be helpful
