annual ring

American  

noun

1. an annual formation of wood in plants, consisting of two concentric layers, one of springwood and one of summerwood.

---

annual ring British  

noun

1. Also called: tree ring.  a ring of wood indicating one year's growth, seen in the transverse section of stems and roots of woody plants growing in temperate climates

---

annual ring Scientific  

1. See under growth ring

---

Etymology

Origin of annual ring

First recorded in 1875–80

Example Sentences

Since the 1960s, researchers have mainly done this recalibration with trees, counting annual rings to get calendar dates and matching those with measured radiocarbon dates.

From Nature

But Pearson's team was able to measure the radiocarbon more precisely, in single, annual rings of three ancient bristlecone pines in California and two oak trees in Ireland.

From Science Magazine

Usual tree-ring dating methods are not suitable for baobabs, because their trunks do not necessarily grow annual rings.

From Nature

Although both the trunk and roots of a tree produce annual rings, they can develop at different rates so it’s not straightforward to correlate their growth.

From National Geographic

It’s in great condition, with tight annual rings in the washed-out, red center.

From Washington Times