Hieracium aurantiacum Linnaeus

Remark The words or terms in red (actually dark orange) in the text are defined in a glossary.


jun_23_14.gthmb can't be loaded. Hieracium aurantiacum is an introduced and naturalized perennial plant with shallow, fibrous roots, stolons, and well-developed basal rosettes. It is native to alpine area of central and southern Europe, where it is protected in several regions.

The plant belongs to the Asteraceae family.

Name

The genus name is said to come form the Greek ιεραξ, the falcon, since the Roman naturalist Gaius Plinius Secundas (Pliny the Elder, AD 23 - August 24, AD 79) believed that the feathery Accipiters (a group of birds of prey in the family Accipitridae, the hawks family notably) fed on plants of this genus to strengthen their eyesight and thus, Hieracium, as named by Pliny the Elder in his Naturalis Historia (34, 114) became the genus name, and by extension the Greek and Latin name of many species of the Hieracium genus, many of these species with the Hawkweed vernacular name.

In Latin, the adjective aurantiacus means orange-colored, the epithet obviously referring to the color of the flower heads.

Common names

Some of the vernacular names of Hieracium aurantiacum are Devil's Paintbrush, Orange Hawkweed, Red Devil, Grim-the-collier, Fox and Cubs, Red Daisy and King-devil. Two French common names are Épervière orangée and Marguerite rouge.

Synonyms

Hieracium aurantiacum has also been known as:

Identification

Hieracium aurantiacum is easy to identify with its orange flower heads, with square-edged notched ray florets, the flower heads clustered at the top of stems covered in stiff black hairs. The distinguishing features of non-flowering plants include the presence of stolons and the numerous short black hairs on the stems. draw.jpg can't be loaded.

Description

Stems

Leaves

Flower heads

Fruits, seeds

Habitat

Hieracium aurantiacum is usually found in mesic to submesic sites; it prefers well- drained soils, growing in permanent meadows, grasslands, rangelands, and pastures, and thrives in nutrient-poor, uncultivated, or disturbed soils.

Distribution

As shown on the map, Hieracium aurantiacum has already [2006] invaded all the Canadian provinces and most states of the USA. map_na.jpg can't be loaded.

Notes

Hieracium aurantiacum was introduced to North America for use as an herbal remedy and ornamental before 1818. Distribution of this weed has likely been assisted by flower enthusiasts due to its beauty. It is native to the alpine and hillside meadows of Europe and has now established across Eurasia, as well as from coast to coast in North America. In Québec, Hieracium aurantiacum is in the list of noxious weeds when they grow in cultivated lands and pastureland.

Hieracium aurantiacum forms a dense mat of plants in which no other species can grow, thereby lowering species diversity and reducing the forage value of grasslands for grazing animals. It is a successful allelopathic competitor that crowds out native, pasture, and range species. It hybridizes freely with native and exotic Hieracium. It likely reduces soil moisture and nutrient availability. It can invade undisturbed sites and is considered one of the worst nuisance species in agricultural and natural areas.

Hieracium aurantiacum have an advantageous reproductive strategy relative to their native counterparts in that they are able to reproduce sexually as well as asexually via vegetative propagation (by stolons, rhizomes, and root buds) and apomixis.

Gallery

The photos of the gallery were taken either with one of the following: Minolta DiMAGE 7, Canon PowerShot A530, Canon Xt Rebel, usually with the EF-S60mm f/2.8 Macro USM objective, Fujifilm A 610 and EPSON Perfection 1650 (scanner). The title in the window shows the date when the picture was taken, i.e. jan_30_06... would mean that the photo was taken on the 30th of January, the 06 is for the 6th picture taken that day. The month, day and picture number might be followed by a letter which I use to identify the system used to take the picture.

Click on the thumbnails to get larger view. The original photos are usually in TIFF format, the photos shown are generally in JPEG format, often of dimensions one half (surface one quarter) for loading time reduction.

Plants

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Leaves

aug_01_01s.mthmb cannot be loaded. The leaves were scanned at 300 dpi, and the dimensions of the resulting picture divided by 2 (area divided by 4); this allows to measure the dimensions of the leaves.

Flower heads

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