trná

Trní is a Czech noun that denotes a thorn or prickle and is used to describe sharp, pointed projections on plants. In everyday language it appears when talking about rose thorns, blackberry canes, hawthorn, and other thorn-bearing vegetation. The word is also found in botanical contexts, where it designates a thorny outgrowth on a stem or branch.

In plant morphology thorns are typically modifications of stems, spines are usually modified leaves, and prickles are outgrowths of the epidermis. This distinction is standard in botanical terminology, though in casual writing the terms are sometimes used loosely. Thorns function primarily as a defense against herbivores and can influence a plant’s growth form by affecting branching and light capture.

Thorns occur across diverse plant families and species. They are especially common in woody shrubs and trees such as many hawthorns (Crataegus), roses (Rosa), and other thorny shrubs, as well as in some Acacia-like taxa in other regions. In cacti and many other succulents, what are commonly called spines play a similar defensive or protective role, though they are not classified as thorns.

Culturally and linguistically, trní figures in descriptions of plant defense and in imagery associated with obstacles or danger. In Czech, the term is part of the ordinary botanical and horticultural lexicon and is translated into English as thorn or prickle, depending on the context.