Thistle (Carline): From the Plant and Flower Alphabet
GRANITE BAY DESIGN PLANT & FLOWER ALPHABET
Thistle is the common name of a group of flowering plants characterised by leaves with sharp prickles on the margins, mostly in the family Asteraceae. Prickles can also occur all over the plant – on the stem and on the flat parts of the leaves. These prickles are an adaptation that protects the plant from being eaten by herbivores. Typically, an involucre with a clasping shape similar to a cup or urn subtends each of a thistle’s flower heads. The typically feathery pappus of a ripe thistle flower is known as thistle-down.
The term thistle is sometimes taken to mean precisely those plants in the tribe Cardueae (synonym: Cynareae), especially the genera Carduus, Cirsium, and Onopordum. However, plants outside this tribe are sometimes called thistles. Biennial thistles are particularly noteworthy for their high wildlife value, producing such things as copious floral resources for pollinators, nourishing seeds for birds like the goldfinch, foliage for butterfly larvae, and down for the lining of birds’ nests.
Engravings from “Handbook of Plant and Floral Ornament from Early Herbals” by Richard G. Hatton (Originally published in 1909).
Plant descriptions primarily from Wikipedia.