Cornus
A beautiful, mixed group of very useful plants, from low growing woody perennials to tall trees. They can be split into roughly three to four groups. Shrubs grown for their coloured stems, such as Cornus sanguinea 'Midwinter Fire'. Trees and shrubs producing clusters of small flowers, surrounded by showy white to pink bracts, from mid-spring through summer. Cornus kousa and cultivars are hard to beat in terms of their all round beauty. A couple of species produce clusters of small yellow flowers (but no showy bracts) and flower late winter to early spring. Cornus mas and C. officinalis, also known as the cornelian cherries. Lastly there are a few low growing, but equally charming, perennials, C. suecica and C. canadensis which produce carpets of small flowers surrounded by white bracts. Interestingly both these diminutive species have exploding seed capsules, enabling their seed to be dispersed further afield.
Cornus species vary in stature, but almost all have flowers that are attractive to pollinating insects, especially bees and flies. They also have fleshy berries which can be an important early winter food supply for garden birds. The leaves are very palatable to invertebrates, supporting a range of moths and the flower buds are one of the hosts of holly blue butterfly caterpillars. Some shrubby species especially C. alba and C. sericea can be invasive in natural habitats and should not be allowed to establish outside the garden.