Family: Daisy & Dandelion [Asteraceae]

toxicity

toxicity

Achillea

Acroptilon

Aetheorhiza

Ageratum

Ambrosia

Anacyclus

Anaphalis

Antennaria

Anthemis

Arctium

Arctotheca

Arctotis

Argyranthemum

Arnoseris

Artemisia

Aster

Baccharis

Bellis

Bidens

Brachyglottis

Buphthalmum

Calendula

Callistephus

Calotis

Carduus

Carlina

Carthamus

Cassinia

Catananche

Centaurea

Chamaemelum

Chrysanthemum

Chrysocoma

Cicerbita

Cichorium

Cirsium

Cladanthus

Cnicus

Conyza

Coreopsis

Cosmos

Cotula

Crepis

Cynara

Dahlia

Delairea

Dichrocephala

Dittrichia

Doronicum

Echinops

Erigeron

Eupatorium

Euryops

Felicia

Filago

Gaillardia

Galactites

Galinsoga

Gazania

Geropogon

Glebionis

Gnaphalium

Grindelia

Guizotia

Hedypnois

Helenium

Helianthus

Helichrysum

Heliopsis

Helminthotheca

Hemizonia

Hieracium

Homogyne

Hypochaeris

Inula

Ismelia

Iva

Lactuca

Lapsana

Leontodon

Leucanthemella

Leuzia

Leucanthemum

Liatris

Ligularia

Madia

Mantisalca

Matricaria

Melampodium

Mycelis

Olearia

Oncosiphon

Onopordum

Osteospermum

Pericallis

Petasites

Picris

Pilosella

Plecostachys

Prenanthes

Pulicaria

Rhagadiolus

Rhodanthe

Rudbeckia

Santolina

Sanvitalia

Saussurea

Schkuhria

Scolymus

Scorzonera

Scorzoneroides

Senecio

Serratula

Sigesbeckia

Silybum

Sinacalia

Solidago

Soliva

Sonchus

Spilanthes

Tagetes

Tanacetum

Taraxacum

Telekia

Tephroseris

Tolpis

Tragopogon

Tripleurospermum

Tussilago

Urospermum

Verbesina

Vittadinia

Xanthium

Xeranthemum

The Daisy or 'Daisy & Dandelion' Family were formerly called Compositae, but are now known by the family name of Asteraceae. The Daisy Family is a very ancient group, thought to have arisen from the now extinct family Calyceraceae about 130 Million years ago in the geological period known as the Cretaceous Period. Species in the Calyceraceae family first arose in Gondwanaland, and were already widely dispersed well before continental drift took a hold and spread them further afield. Fossils from the Calyceraceae family are found in Europe, Africa, Australia and North America. The Asteraceae Family is an extremely abundant group, comprising 10% of the species of flowering plants, encompassing dandelions, chrysanthemums, marigolds, sun-flowers, ragworts, fleabanes, thistles, wormwoods, cudweeds, groundsels, chamomiles, sow-thistles and many others. The vast majority are herbaceous flowers; there are very few tree-forms amongst them. Perhaps the most remarkable feature of the Daisy Family, and un-like any other member of the Dicotyledons, is the composition of the flower head. A typical flower head is exemplified by the common daisy: the central yellow part comprises a great many vertical tubes (called discs by biologists). These are the actual functional flowers themselves. Surrounding the central yellow portion are what appear to be white 'petals' which are actually not petals at all but more flowers, this time they are sterile flowers. Biologists call these rays. (In other plants of the daisy family, not all discs are yellow, nor all rays white). No other Family of plants has this composite arrangement of sterile and non-sterile flowers, thought by some to be the pinnacle of flower evolution. This compsite arrangement of the flowers gave rise to the now obsolete term Compositae for this family.

Many members of the Asteraceae family have allergenic compounds in their sap called sesquiterpene lactones (of which there are hundreds) that are able to cause contact dermatitis in some susceptible people. Thus: Dandelion contains the allergen Taraxinic Acid, which may have application in the treatment of leukemia. Dandelions have been known to cause allergic reactions and contact dermatitis due to this toxic component. Feverfew contains the allergen Parthenolide Perennial Ragwood (Ambrosia Psilostachya) [not yet linked to] contains the allergen Isabelin. Chamomile [not yet linked to] contains the allergen Nobilin, a Sesquiterpene Lactone. Annual Sunflower (Helianthus Annuus) [not yet linked to] contains the allergen Niveusin. Lettuce (Lactuca Sativa) [not yet linked to] contains the allergen Lactucopicrin. It is also a component of the latex-like sap called Lactucarium obtained from Great Lettuce, which has been used in cough medicines. Chicory contains Lactucin, a bitter substance. Indeed, so many and varied are the sesquiterpene lactones in the Daisy Family that one researcher has based a chemical taxonomy on the exact sequiterpene lactone(s) present in each species. [Although personally, I don't think any taxonomy can possibly describe species if they have, at some ancient or modern time in the past, been swapping genes back and forth, and both vertically and horizontally across the family tree(s)? If that is so, all attempts at classification and the construction of family trees are doomed to failure].