subtend

The side of a triangle subtends the opposite angle.

三角形的边对着对角

flowers subtended by leafy bracts.

花被包在叶苞内

In the daisy family the numerous bracts which subtend the inflorescence are known as an involucre.

在菊科物中，苞片数目多而聚生在花序外围，称为总苞。

18(17) Inflorescence subtended by a broad, 2-keeled prophyll; rachilla internodes usually distinct and disarticulating.

花序被包着以一宽阔的部分，2龙骨状；小穗轴节间通常脱节。