Linnaea borealis is a species of flowering plant in the family Caprifoliaceae (the honeysuckle family). It is the only species in the genus Linnaea. It is a boreal to subarctic woodland subshrub, commonly known as twinflower (sometimes written twin flower).
This plant was a favourite of Carl Linnaeus, founder of the modern system of binomial nomenclature, after whom the genus was named.
A subshrub (Latin suffrutex), undershrub, or shrublet is either a small shrub (e.g. prostrate shrubs) or a perennial that is largely herbaceous but slightly woody at the base (e.g. garden pink and florist's chrysanthemum). The term is often interchangeable with "bush".
Because the criteria are matters of degree (typically height) rather than kind, the definition of a subshrub is not sharply distinguishable from that of a shrub; examples of reasons for describing plants as subshrubs include ground-hugging stems or a low growth habit. Subshrubs may be largely herbaceous, although still classified as woody, with overwintering perennial woody growth that is much lower-growing than the deciduous summer growth. Some plants described as subshrubs are only weakly woody, and some persist for only a few years at most. Others, such as Oldenburgia paradoxa, live indefinitely (though they are still vulnerable to external effects), rooted in rocky cracks.