Senna artemisioides -- California
There was not much information found assessing how invasive Senna artemisioides may be in areas across the world where it is not native.
Euphorbia hypericifolia -- California
The common horticultural container plant Euphorbia ‘Diamond Frost’ is sometimes attributed to Euphorbia hypericifolia but it is not closely related (CDFA). Ron Vanderhoff suspects that Euphorbia is marginally adapted to xeric conditions and will likely become a common urban weed but will only marginally establish in wildlands (2022).
CABI:
https://www.cabi.org/isc/datasheet/119929
Accessed 09/23/2022
Pennisetum ciliare -- California
Websites accessed:
Pennisetum ciliare (L.) Link in GBIF Secretariat (2021). GBIF Backbone Taxonomy.
Senecio angustifolius -- California
These is a scarcity of published date about this species natural history or invasiveness, making several of these questions either unanswered or with a low confidence score. Outside of its native South Africa, California appears to be the only location the species has naturalized, making us perhaps an early indicator for other similar climate areas of the world.
Briefly mentioned in Questions 1, 2, 3, and 4 are what I am considering dubious occurrence records in Mexico, Germany, Spain, and Taiwan:
Caesalpinia spinosa -- California
Question 11: I only found one source (Balaguer et al. 2011) that stated this plant can reproduce vegetatively. Most other sources only discuss propagation via seeds, however they don't specify whether other methods are possible. I found conflicting information on the New Zealand Plant Conservation Network that states this plant only reproduces via seed.
Lathyrus nissolia -- California
Evaluator's note: This evaluation was difficult to conduct because of the general lack of information available on the species. Lathyrus nissolia may eventually be re-evaluated as a high risk once its impacts are better known.
Adonis aestivalis -- California
Calflora: https://www.calflora.org/app/taxon?crn=104 Accessed: 07/21/2022 GBIF: https://www.gbif.org/species/5371707 Accessed: 07/21/2022 iNaturalist: https://www.inaturalist.org/taxa/57426-Adonis-aestivalis Accessed: 07/21/2022 Jepson eFlora: https://ucjeps.berkeley.edu/eflora/eflora_display.php?tid=11986 Accessed: 07/21/2022 Outside Pri