KanjiJLPT N1
Stem

for the most part, close up, flower stem

Mnemonic

A tree must renew its growth each spring. The first sign? A rigid stem shoots out, firm and unyielding. This stem stands so stiff it blocks sunlight from the branches below — an obstruction born from the tree's own renewal.
Additional thoughts
Picture a tree in spring: its renewed growth produces one dominant stem so thick and rigid it actually obstructs the lower branches. The stem is both life-giving support and stubborn blockage.
Quick recall
A tree that renews itself pushes out one tough, obstructing stem.

Details

The keyword for 梗 is stem. This kanji refers to the stalk or stem of a plant, particularly the firm, straight part that supports it. By extension, it can also carry the meaning of something that blocks or obstructs, much like a rigid stem that stands in the way. In modern usage, it often appears in words related to blockages, such as in medical terms describing obstructions like cerebral infarctions.
On'yomi
こう、きょう
Kun'yomi
ふさぐ、やまにれ、おおむね