involute

Several daguerreotypes here foreground the ornament and patterning of Egyptian buildings; this one captures every edge of the involute roof of a 16th-century mosque, festooned with knotty hearts and flowers.

They were involute, introvert, indirect; they did not like questions and answers.

Ours perennials, 1–2° high, with narrow and soon involute leaves, hairy sheaths bearded at the throat, and a small simple panicle or raceme of about 7-flowered spikelets.

Draw setting tangent from “base circle” of involute, at middle of tooth.

The first curve is called the involute of the second.