Belongs within: Heliantheae.
The Ambrosiinae are a group of composite plants with reduced flowerheads specialised for wind pollination.
Characters (Black & Robertson 1965): Heads unisexual or androgynous; receptacle with chaffy scales; corolla tubular in males, absent or reduced in females; anthers obtuse at base, free or scarcely coherent; pappus absent; leaves mostly alternate.
<==Ambrosiinae [Ambrosieae]
|--Dicoria canescensN10, B14 [incl. D. canescens ssp. clarkiaeH93, D. canescens ssp. hispidulaH93]
|--IvaBR65
| |--I. acerosa (Nutt.) Jackson 1960M68 [=Oxytenia acerosaH93]
| |--I. annuaRJ11
| |--I. axillarisBR65
| | |--I. a. ssp. axillarisH93
| | `--I. a. ssp. robustiorH93 [incl. I. axillaris var. pubescensM68]
| |--I. hayesianaH93
| |--I. nevadensisH93
| `--I. xanthiifoliaV09
|--XanthiumN10
| |--X. californicumBR65
| |--X. indicumC55
| |--X. macrocarpumC55
| |--X. orientaleBR65
| |--X. pinnataM99
| |--X. pungensBR65
| |--X. spinosumBR65
| `--X. strumarium [incl. X. strumarium var. canadense, X. strumarium var. glabratum]H93
`--AmbrosiaRJ11
|--A. acanthicarpa [=Franseria acanthicarpa]H93
|--A. ambrosioides [=Franseria ambrosioides]H93
|--A. artemisiifoliaRJ11
|--A. chamissonis [=Franseria chamissonis; incl. A. bipinnatifida, A. chamissonis ssp. bipinnatisecta]H93
|--A. chenopodiifolia [=Franseria chenopodiifolia]H93
|--A. confertiflora [=Franseria confertiflora]H93
|--A. deltoideaBT72
|--A. dumosa [=Franseria dumosa]H93
|--A. eriocentraH93 [=Franseria eriocentraM68]
|--A. ilicifolia [=Franseria ilicifolia]BT72
|--A. magdalenaeB71
|--A. psilostachyaBR65
| |--A. p. var. psilostachyaM68
| `--A. p. var. californicaM68
|--A. pumilaH93
|--A. tenuifoliaC55
`--A. trifidaBT72
*Type species of generic name indicated
References
[BT72] Baker, E. W., & D. M. Tuttle. 1972. New species and further notes on the Tetranychoidea mostly from the southwestern United States (Acarina: Tetranychidae and Tenuipalpidae). Smithsonian Contributions to Zoology 116: 1–37.
[BR65] Black, J. M., & E. L. Robertson. 1965. Flora of South Australia. Part IV. Oleaceae–Compositae. W. L. Hawes, Government Printer: Adelaide.
[B71] Bostic, D. L. 1971. Herpetofauna of the Pacific coast of north central Baja California, Mexico, with a description of a new subspecies of Phyllodactylus xanti. Transactions of the San Diego Society of Natural History 16 (10): 237–264.
[B14] Bouchard, P. (ed.) 2014. The Book of Beetles: A lifesize guide to six hundred of nature’s gems. Ivy Press: Lewes (United Kingdom).
[C55] Candolle, A. de. 1855. Géographie Botanique Raisonée: Ou exposition des faits principaux et des lois concernant la distribution géographique des plantes de l’époque actuelle vol. 2. Librairie de Victor Masson: Paris.
[H93] Hickman, J. C. (ed.) 1993. The Jepson Manual: Higher Plants of California. University of California Press: Berkeley (California).
[M99] Matthews, M. 1999. Heliothine Moths of Australia: A guide to bollworms and related noctuid groups. CSIRO Publishing.
[M68] Munz, P. A. 1968. Supplement to a California Flora. University of California Press.
[N10] Norrbom, A. L. 2010. Tephritidae (fruit flies, moscas de frutas). In: Brown, B. V., A. Borkent, J. M. Cumming, D. M. Wood, N. E. Woodley & M. A. Zumbado (eds) Manual of Central American Diptera vol. 2 pp. 909-954. NRC Research Press: Ottawa.
[RJ11] Rising, J. D., A. Jaramillo, J. L. Copete, P. G. Ryan & S. C. Madge. 2011. Family Emberizidae (buntings and New World sparrows). In: Hoyo, J. del, A. Elliott & D. A. Christie (eds) Handbook of the Birds of the World vol. 16. Tanagers to New World Blackbirds pp. 428–683. Lynx Edicions: Barcelona.
[V09] Verdcourt, B. (ed.) 2009. Additions to the wild fauna and flora of the Royal Botanic Gardens, Kew. XXVI. Miscellaneous records. Kew Bulletin 64 (1): 183–194.