Baccharis
Baccharis is a genus of perennials and shrubs in the aster family (Asteraceae). They are not at all related to these however, but belong to an entirely different lineage of eudicots. B. halimifolia is commonly known as "groundsel bush", however true groundsels are found in the genus Senecio.
Baccharis, with over 500 species, is one of the largest genera in the Asteraceae.
It is found throughout the Americas, distributed mainly in the warmer regions of Brazil, Argentina, Colombia, Chile and Mexico, with B. halimifolia ranging northward along the Atlantic Coast to the southern tip of Nova Scotia in Canada.
If present, the leaves of Baccharis are borne along the stems in alternate fashion. Flowers are usually white or pinkish. There are no ray flowers, but many disk flowers which are either staminate or pistillate.
Some species of Baccharis are toxic to animals; in particular, consumption of B. coridifolia may lead to necrosis in the gastrointestinal tract of cattle, horses, sheep, and rabbits.
The genus Baccharis is named after Bacchus (Dionysus), the Roman god of wine.
Classification
Baccharis is related to the genera Archibaccharis and Heterothalamus.All Baccharis are dioecious except Baccharis monoica.
Ecology
Baccharis are used as food plants by the larvae of some Lepidoptera species, such as the swift moths Phymatopus californicus and P. hectoides. Those of the leaf-miner moths Bucculatrix dominatrix and B. seperabilis feed exclusively on bush baccharis, B. ivella has been found on eastern baccharis, and B. variabilis is a polyphagous species which has been recorded on various Baccharis. The Coleophora case-bearers C. linosyridella and C. viscidiflorella are polyphagous species whose larvae have been recorded on the Bush Baccharis as well as other plants. Caterpillars of the owlet moth Schinia ocularis feed exclusively on broom baccharis.Baccharis conferta, native to Mexico, was chosen to serve as nurse plants to protect from frost and drought newly planted tree seedlings of Abies religiosa in the world's first assisted migration experiment that coupled upslope planting of the fir tree in anticipation of climate change forcing overwintering Monarch butterflies to seek higher elevations in central Mexico.
Uses
Several species of Baccharis are of interest for cultivation, as the dense but flexible stem structure makes for a good windbreak.Plants of this genus are rich in terpenes, and some are used in native or folk medicine. One that has been specifically described from Chilean and Argentinean Baccharis is viscidone.
Baccharis flowers are rich in nectar, and several species are good honey plants. Particularly B. dracunculifolia is highly esteemed by beekeepers.
Conservation
A few Baccharis species are almost extinct due to habitat destruction. The northernmost occurrence of B. halimifolia, in Nova Scotia, Canada, is also receiving conservation attention.Invasiveness
Some Baccharis species, particularly Eastern baccharis (B. halimifolia), have become invasive weeds in places such as Australia and Spain, where they are not native.Selected species
For the complete list of species see List of Baccharis species.Image:Baccharis details5.jpg|thumb|right|Baccharis rhomboidalis inflorescencesBaccharis acutata BorhidiBaccharis alaternoides KunthBaccharis albida Hook. & Arn.Baccharis × alboffii F.H.Hellw.Baccharis albolanosa A.S.Oliveira & DebleBaccharis aliena Joch.Müll.Baccharis alleluia A.S.Oliveira & DebleBaccharis alnifolia Meyen & Walp.Baccharis alpestris GardnerBaccharis alpina KunthBaccharis altimontana G.Heiden, Baumgratz & R.EstevesBaccharis amambayensis Zardini & SoriaBaccharis anabelae G.HeidenBaccharis angusticeps Dusén ex MalmeBaccharis angustifolia MichauxBaccharis anomala DC.Baccharis antioquensis Killip & Cuatrec.Baccharis × antucensis F.H.Hellw.Baccharis aphylla DC.Baccharis apicifoliosa A.A.Schneid. & BoldriniBaccharis aracatubensis Malag. & Hatschb. ex G.M.BarrosoBaccharis arbutifolia VahlBaccharis × arcuata F.H.Hellw.Baccharis arenaria BakerBaccharis aretioides Turcz.Baccharis artemisioides Hook. & Arn.Baccharis articulata Pers.Baccharis auriculigera Hieron.Baccharis × australis F.H.Hellw.Baccharis axillaris DC.Baccharis ayacuchensis Cuatrec.Baccharis barragensis Cuatrec.Baccharis beckii Joch.Müll.Baccharis bicolor G.HeidenBaccharis bifrons BakerBaccharis bigelovii A.GrayBaccharis bogotensis KunthBaccharis boliviensis CabreraBaccharis boyacensis Cuatrec.Baccharis brachylaenoides DC.Baccharis brachyphylla A.GrayBaccharis brachystachys Malag. & J.VidalBaccharis brevifolia DC.Baccharis brevipappa G.L.NesomBaccharis breviseta DC.Baccharis buchtienii H.Rob.Baccharis burchellii BakerBaccharis buxifolia Pers.Baccharis cabrerae ArizaBaccharis caespitosa Pers.Baccharis concava Pers.Baccharis dioicaBaccharis douglasii DC. - Saltmarsh baccharis, Douglas' baccharisBaccharis dracunculifolia DC.Baccharis eggersii Hieron.Baccharis emoryi A.GrayBaccharis fusca Turcz.Baccharis genistelloides Pers.Baccharis glomerulifloraBaccharis glutinosa Baccharis gracilis DC.Baccharis halimifolia L. - Eastern baccharis, groundsel bush, groundsel tree, consumption weed, cotton-seed tree, silverlingBaccharis hambatensis KunthBaccharis havardiiBaccharis hieronymi HeeringBaccharis huairacajensis Hieron.Baccharis humilis Sch.Bip. ex BakerBaccharis intermedia DC.Baccharis intermixta GardnerBaccharis juncea Desf.Baccharis klattii BenoistBaccharis ligustrina DC.Baccharis linearis Pers. - Chilean romerilloBaccharis macraei Hook. & Arn.Baccharis malibuensis R.M.Beauch. & J.HenricksonBaccharis microdonta DC.Baccharis myrsinitesBaccharis neglectaBaccharis odorata - Tayanka bushBaccharis patagonicaBaccharis pilularis DC. - Bush baccharis, coyote brush, coyote bush, chaparral broomBaccharis platypoda DC.Baccharis plummerae A.GrayBaccharis pteronioidesBaccharis punctulata DC.Baccharis racemosa DC.Baccharis rhomboidalis RemyBaccharis sagittalisBaccharis salicifolia Pers. - Mulefat, seep-willow, water-wallyBaccharis salicinaBaccharis sarothroides A.Gray - Broom baccharis, Desert broomBaccharis semiserrata DC.Baccharis sergiloides A.Gray - Desert baccharisBaccharis serrula Sch.Bip.Baccharis sessifolia L.Baccharis sphaerocephalaBaccharis spicata Baill.Baccharis texana Baccharis thesioidesBaccharis tricuneata Pers.Baccharis tridentata VahlBaccharis trimera DC.Baccharis uncinella DC.Baccharis vanessae R.M.Beauch.Baccharis wrightii - Wright's false willowBaccharis wurdackeana Malag.Baccharis xiphophylla Baker Baccharis zamoranensis Rzed.Baccharis zamudiorum Rzed.Baccharis zoellneri F.H.Hellw.Baccharis zongoensis Joch.Müll.Baccharis zumbadorensis V.M.Badillo