Archivos de diario de noviembre 2022

30 de noviembre de 2022

On Identifying Queen Anne's Lace (= Wild Carrot = Daucus carota)

iNaturalist has over 14,000 "needs ID" observations of Daucus in North America, although we have only two Daucus species and one (D. carota) is abundant and usually easily identified. Please help get more of these identified!

Here are some things I learned when working on this.

A. Daucus carota has an array of tiny white flowers, the ones on the outer edges a little enlarged. Lots of other plants have the same pattern, so this by itself isn't enough for identification.

B. Daucus carota often has a dark purple flower in the very center. If present, this allows identification! (in North America) Its absence means nothing, though. Example: https://www.inaturalist.org/observations/143044211

C. The bracts at the base of the flower cluster (compound umbel) in Daucus carota are moderately long and have 3 to 7 slender lobes. Example: https://www.inaturalist.org/observations/142548223 This is unusual in North American members of the Carrot Family, so if the plant looks good otherwise, this will tip me over to identifying it as D. carota.

D. The nest-like structure formed as the seeds mature is distinctive -- the easiest way to identify Daucus carota! Example: https://www.inaturalist.org/observations/143284547 Late in the fall, the outer branches may spread out again. CAUTION: Visnaga daucoides, introduced to California and the Gulf Coast has slender nest-like fruiting heads, but each has a whole tangle of many, many bracts at the base and the seeds have very short bristles. CAUTION: In the native annual Daucus pusillus the fruiting structure is similar but flatter, more cup-like, and very dense, with shorter bracts with short lobes.

E. Daucus carota stems are coarsely hairy. That's not enough to identify one, but it it's smooth, it's not D. carota.

F. In the Carrot Family, leaves are often useful for identification. Unfortunately, Daucus carota leaves look a lot like those of some other species, including the weed Scandix pecten-veneris. (On the other hand, leaves that look like D. carota leaves and are posted as D. carota leaves usually are D. carota leaves . . . . )

Similar species:

The Texas endemic Daucosma laciniata has pinnately divided bracts and bractlets like Daucus carota. It differs in having much less divided leaves and glabrous fruits, and its inflorescences don't form a nest-like structure in fruit.

Daucus pusillus is smaller, lacks the purple center flower, and has more divided bracts that usually have blunt tips and are usually longer than the cluster of flowers or fruits. It grows on both coasts. It also grows along the Gulf Coast and north to at least Oklahoma.

Visnaga daucoides (= Ammi visnaga), introduced to California and the Gulf Coast has slender nest-like fruiting heads, but each has a whole tangle of many, many bracts at the base and the seeds have very short bristles.

Ingresado el 30 de noviembre de 2022 por sedgequeen sedgequeen | 8 comentarios | Deja un comentario