Hieracium , known by the common name hawkweed and classically as hierakion, is a genus of the sunflower (Helianthus) family Asteraceae), and closely related to dandelion (Taraxacum), chicory (Cichorium), prickly lettuce (Lactuca) and sow thistle (Sonchus), which are part of the tribe Cichorieae. Hawkweeds, with their 10,000+ recorded species and subspecies, do their part to make Asteraceae the second largest family of flowers. Some botanists group all these species or subspecies into approximately 800 accepted species, while others prefer to accept several thousand species. Since most hawkweeds reproduce exclusively asexually by means of seeds that are genetically identical to their mother plant, clones or populations that consist of genetically identical plants are formed and some botanists prefer to accept these clones as good species whereas others try to group them into a few hundred more broadly defined species. What is here treated as the single genus Hieracium is now treated by most European experts as two different genera, Hieracium and Pilosella, with species such as Hieracium pilosella, Hieracium floribundum and Hieracium aurantiacum referred to the latter genus. Many members of the genus Pilosella reproduce both by stolons and by seeds, whereas true Hieracium species reproduce only by seeds. In Pilosella, many individual plants are capable of forming both normal sexual and asexual (apomictic) seeds, whereas individual plants of Hieracium only produce one kind of seeds. Another difference is that all species of Pilosella have leaves with smooth (entire) margins whereas most species of Hieracium have distinctly dentate to deeply cut or divided leaves.
A dry roadside dotted with small, ¾ inch red orange flowers, interspersed with very similar yellow ones, and often the white of daisies, is a good sign that you are in Hawkweed country.
Hieracium lachenalii, also known as common hawkweed or yellow hawkweed, is a species of plant in the dandelion tribe within the sunflower family. It is native to Europe but has become established as a weed in Australia and parts of North America. The species was widely known for many years as H. vulgatum, but more recent studies have indicated that the two names represent the same species. The name H. lachenalii was coined in 1802, H. vulgatum in 1819, so the older name is to be used.
Pilosella caespitosa is like several other Pilosella species and has a similar appearance to many of the hawkweeds.
Hieracium albertinum, known as western hawkweed or houndstongue hawkweed, is a species of the genus Hieracium that is very similar to Hieracium albiflorum with white flowers but differs in that the flower heads are clustered and the leaves, stems and bracts are covered in a thick layer of hairs. Standing 1 inch (3 cm) to 5 inches (13 cm) tall, it can be found blooming from June through August in forest clearings.
Pilosella horrida, known as the prickly hawkweed or shaggy hawkweed, gets its name from the long, dense, shaggy white to brown hairs (trichomes) which cover all of the plant parts of this plant species. The species is native to Oregon, California, and Nevada in the western United States.
Hieracium greenei is a species of hawkweed known by the common name Greene's hawkweed.
Hieracium argutum is a species of flowering plant in the aster family known by the common name southern hawkweed.
Hieracium venosum is a species of hawkweeds in the dandelion tribe within the sunflower family. It is widespread and common in south-central Canada (Ontario) and the eastern United States. Its common name comes from the fact that environments it is found in are typically also a home to rattlesnakes.
Veratrum hybridum is a species of flowering plant in the Melanthiaceae known by the common names slender bunchflower and crisped bunchflower. Many publications use the synonyms Melanthium latifolium and Veratrum latifolium, but the "hybridum" epithet is 9 years older than the "latifolium," so Veratrum hybridum is now the accepted name.
Blephilia hirsuta is an herbaceous perennial of the mint family Lamiaceae native to eastern North America. It is commonly called hairy wood-mint or hairy pagoda plant.
Hieracium murorum, the wall hawkweed, is a species of flowering plant in the sunflower family. It is native to Europe and naturalized in some of the colder regions of North America.
Doellingeria infirma, the cornel-leaf whitetop or cornel-leaved aster, is a perennial forb native to the eastern United States, that produces white composite flowers in late summer.
Sericocarpus linifolius is a perennial forb native to the eastern United States, that produces white composite flowers in summer.
Cardamine douglassii, the limestone bittercress or purple cress, is a perennial forb native to the eastern and central United States as well as the province of Ontario in Canada, that produces white to pink or purple flowers in early spring.
Chaerophyllum procumbens, known by the common names spreading chervil and wild chervil, is an annual forb native to the eastern United States and Canada, which produces small white flowers in spring.
Clitoria mariana, is a perennial forb.
Penthorum sedoides, known by the common name ditch stonecrop, is a perennial forb native to the eastern United States and Canada which produces small white flowers in summer.
Hieracium longiberbe, known by the common name longbeard hawkweed, is a rare North American plant species in the dandelion tribe within the sunflower family. It has been found only in the Columbia River Gorge along the border between the states of Washington and Oregon in the northwestern United States.
Hieracium longipilum, the hairy hawkweed, is a North American plant species in the dandelion tribe within the sunflower family. It is widespread across much of central Canada and the central United States from Ontario south to Texas and Louisiana. There are old reports of the species growing in Québec, but apparently does not grow there now.
Hieracium pringlei, common name Pringle's hawkweed, is a North American plant species in the dandelion tribe within the sunflower family. It is native to Mexico with additional populations in Guatemala, Arizona, and New Mexico.
