Tuesday, August 14, 2012

Picris hieracioides

This is an invasive, alien weed and I generally pull it out when I have time. It resembles a tall, multi-headed dandelion with rough-hairy, almost bristly, stems and leaves. Indeed it is a relative and like dandelions, comes from a foreign land. This one is native to the mountains in southern Spain and northern Portugal. In addition to growing in my yard, I find it proliferating along roadsides, often intermingled with its close relative, blue Chicory. The combination is colorfully attractive. All these plants are in the Aster (Daisy) family and generally considered invasive weeds.

I learned it's name as "Hawkweed Picris" from a botany professor, but the rest of the world now seems to call it "Hawkweed Oxtongue." Sorry, that just doesn't have the same ring (or is it just habit)?  The scientific name is Picris hieracioides. The genus name (Picris) comes from a Greek word for bitter, referring to the plant's roots. Members of this genus are called "oxtongues." The species name indicates its close resemblance to hawkweeds, genus Hieracium.

We've described the flowers as dandelion-like, but look closely and notice that the tip of each yellow ray has five "teeth." With age, the blossom becomes a fuzzy seed head. Without adequate sunlight, though, the plant never reaches the flowering stage and remains a basal rosette of leaves (on the ground).

The lower stem leaves are long, lance-shaped and wavy-edged, or they have short teeth separated by scalloped sinuses (see the last images before the photo notes). The upper leaves are shorter, alternate, long arrow-shaped and hug the main stem. Side branches arise from the points of attachment [axils].

Picris is a biennial, taking two years to reach maturity in sunny, open yards, fields and roadsides, and sometimes it survives another year or two as a short-lived perennial. It is related to Chicory (genus Cichorium) and both are in the Chicory subfamily (Cichorioideae).

Picris is found in isolated pockets across the Northeast into Canada, but primarily in New York and Pennsylvania. There is a disconnected invasion, again highly localized, in the Northwest from Washington to Alaska and another in Hawaii.

Photo notes: To make a leaf stand out, cast a shadow into the background. Use a tripod and a cable release [or the self-timer]. After aiming and setting the exposure [manual works best], move to throw your shadow into the background. After taking the shot, check the result and adjust as needed. I've also used notebooks and shirts to create shadows where I need them.
Lenses for this project were the 18-55mm kit lens and 100mm macro on a Canon XT.

Corrections, comments and questions are always welcome at northeastnaturalist@yahoo.com Connect with me on Facebook. In addition to my personal page (with the Gaillardia flower at the top), there is a photo/artist page, Dave Spier (photographic naturalist).

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