Looks like one of the dastardly shrub honeysuckles (Lonicera spp.) to me, probably winter or fragrant honeysuckle. That one is known as Lonicera fragrantissima. It will have had small creamy white flowers earlier in your season, from which the red fruit are now forming. The new stem growth extensions with purplish color is the give-away ID to me. All the honeysuckles are oppositely arranged in leaf and branching, making them easy to separate from many other native species (except viburnums, buckeyes, and dogwoods, of course). The behavior of "...the shrubby undergrowth is almost entirely this shrub..." fits with how many shrub honeysuckles dominate the understory of woodlands when they get the chance. The term that fits is invasive. If you are interested in reducing or eliminating this effect, then you have to reduce/eliminate the flowering so that you don't have massive new fruit production every year. That means repetitive cutting down of the plants, especially right before or during flowering, or resorting to total removal or pesticide application.

Looks like one of the non-native shrub honeysuckles. Considered invasive in most places where it occurs. Consider just digging it up and trashing it.

artdeco, it's hard for me to see the size and shape of the berries, as it's on the side of this house and I've only seen it from the street. It appears to be covered in berries and looks to be about 6 feet tall. The shape is hard to explain, the more I look at it, the more is appears to be a little stragely rather than dense and compact. It probably is a winterberry bush. From what I've read, winterberries aren't really a favorite of the birds, at least not until late in the winter when all else has been eaten. I love the looks and color of the shrub I've been seeing, the berries are so bright, you can see them from down the street. It almost looks like the shrub is covered with bright red flowers. I'm pretty sure I will purchase a male and female in the spring. I will have to investigate the best ones to get for zone 5. Linda

Thanks, Jane. The winterberry may well be another of those native plants that would much rather have a nice, moist environment but will make do with whatever it can get so long as it's not too dry. Mine was probably a volunteer from the wild that my mother left in place many years ago. I suspect there is some underground water there; possibly originally from the house next door which is higher, but now there's a septic leach field nearby to please anything with deep roots. I have three, maybe four seedlings that appeared in beds I keep moderately watered and I'm hoping that at least one of these will be a male for a pollinator. I have no idea where the current male is and I'm afraid the bees have a long journey between them. Claire Here is a link that might be useful: Ilex verticillata at hortuconn