Main navigation

  • Home
  • About
    • Methodology
    • History of PRE
  • Evaluations
  • Plants
  • Organizations
  • Community
  • Projects

User account menu

  • Log in
PRE — Plant Risk Evaluator

Matthiola parviflora -- Arizona

Evaluation Summary


Evaluation Date:  2026-06-10

Screener:  Anthony Dant
 
Plant:  Matthiola parviflora
Common Name(s):
smallflower stock

State:  Arizona

PRE Score:  6
Questions Answered:  19
Screener Confidence (%):  71

Executive Summary

Matthiola parviflora is an annual forb from the Brassicae family that is native to northern Africa and southern Europe. Though there is evidence of long-standing populations of it in Arizona, particularly in Tucson, and is reported as an invasive species, it has yet to be declared by the State as one. Matthiola parviflora is a small, herbaceous plant that prefers disturbed, sandy habitat in Arizona with its first record being found near the University of Arizona Desert Laboratory in 1903. While there is a great published article from Horst et al. 2014 describing the species within southern Arizona, there is a notable lack of work on the biology and reproductive life history of this species. In addition, research on the genus Matthiola is lacking. Further peer reviewed work on this species’ life history and interactions with native flora and fauna will necessary to assess potential for this species invasion status in the state of Arizona.

Climate Matching Map

https://weedmap.cal-ipc.org/temp/5368100b866c1b3af4adb43fb5a9b767/ClimateMatch-…
Attachment Size
climatematch-matthiola_parviflora-united_states___arizona-20260610.pdf (1.27 MB) 1.27 MB

1. Question 1

No
0
Medium
No. This species is currently concentrated in its native range across Spain and Northern Africa. While there are currently reports of Matthiola parviflora growing in Arizona, there has not been confirmed naturalization for the species yet . Populations for the species are particularly present in southern Arizona around Tucson (with reports of if being found first at the University of Arizona Desert Laboratory).
Horst, Jonathan L., Sarah Kimball, Judith X. Becerra, Koji Noge, and Lawrence Venable. (2014) 2014. “Documenting the Early Stages of Invasion of Matthiola Parviflora and Predicting Its Spread in North America”. The Southwestern Naturalist 59 (1). doi:https://doi.org/10.1894/F07-FMO-13.1.
Flora, Southwest. 2020. “Matthiola Parviflora”. https://southwestdesertflora.com/WebsiteFolders/All_Species/Brassicacea….

2. Question 2

Yes
2
Very High
Yes, Matthiola parviflora occurs within southern Europe and northern Africa (occurring in both Mediterranean and desert ecosystems). This mirrors climate of its current distribution in Arizona.
Horst, Jonathan L., Sarah Kimball, Judith X. Becerra, Koji Noge, and Lawrence Venable. (2014) 2014. “Documenting the Early Stages of Invasion of Matthiola Parviflora and Predicting Its Spread in North America”. The Southwestern Naturalist 59 (1). doi:https://doi.org/10.1894/F07-FMO-13.1.
Flora, Southwest. 2020. “Matthiola Parviflora”. https://southwestdesertflora.com/WebsiteFolders/All_Species/Brassicacea….

3. Question 3

No
0
High
No. While it is currently reported as invasive in Arizona as noted in Horst et al. 2014 and by the National Park Service, it has not been designated as invasive yet. In addition, the species is also designated as a global weed by Randall 2017 but not invasive.
Horst, Jonathan L., Sarah Kimball, Judith X. Becerra, Koji Noge, and Lawrence Venable. (2014) 2014. “Documenting the Early Stages of Invasion of Matthiola Parviflora and Predicting Its Spread in North America”. The Southwestern Naturalist 59 (1). doi:https://doi.org/10.1894/F07-FMO-13.1.
Flora, Southwest. 2020. “Matthiola Parviflora”. https://southwestdesertflora.com/WebsiteFolders/All_Species/Brassicacea….

4. Question 4

No
0
Low
No. While this species may have the potential to be labeled as invasive in Arizona (focused in southern Arizona) in the future, currently it not designated as an invasive species within the US or globally.
Horst, Jonathan L., Sarah Kimball, Judith X. Becerra, Koji Noge, and Lawrence Venable. (2014) 2014. “Documenting the Early Stages of Invasion of Matthiola Parviflora and Predicting Its Spread in North America”. The Southwestern Naturalist 59 (1). doi:https://doi.org/10.1894/F07-FMO-13.1.
Flora, Southwest. 2020. “Matthiola Parviflora”. https://southwestdesertflora.com/WebsiteFolders/All_Species/Brassicacea….

5. Question 5

No
0
Very High
No. There are no other members within the Matthiola genus that are currently invasive within a similar climate.
Horst, Jonathan L., Sarah Kimball, Judith X. Becerra, Koji Noge, and Lawrence Venable. (2014) 2014. “Documenting the Early Stages of Invasion of Matthiola Parviflora and Predicting Its Spread in North America”. The Southwestern Naturalist 59 (1). doi:https://doi.org/10.1894/F07-FMO-13.1.
Flora, Southwest. 2020. “Matthiola Parviflora”. https://southwestdesertflora.com/WebsiteFolders/All_Species/Brassicacea….
2026. “Brassica Tournefortii”. https://www.cal-ipc.org/plants/profile/brassica-tournefortii-profile/.

6. Question 6

No
0
Very High
No. Despite its invaded range being found in Arizona, the majority of documented locations for this species fall outside of Arizona's climate range, though there is some overlap in Spain's arid regions.
Horst, Jonathan L., Sarah Kimball, Judith X. Becerra, Koji Noge, and Lawrence Venable. (2014) 2014. “Documenting the Early Stages of Invasion of Matthiola Parviflora and Predicting Its Spread in North America”. The Southwestern Naturalist 59 (1). doi:https://doi.org/10.1894/F07-FMO-13.1.
Flora, Southwest. 2020. “Matthiola Parviflora”. https://southwestdesertflora.com/WebsiteFolders/All_Species/Brassicacea….

7. Question 7

No
0
Medium
There is little evidence or research of species and even less so with its interactions with the community. Further work is needed to uncover the whole effect this species has within its invasive range. For now, based on its small size, we can assume no for this answer.
Horst, Jonathan L., Sarah Kimball, Judith X. Becerra, Koji Noge, and Lawrence Venable. (2014) 2014. “Documenting the Early Stages of Invasion of Matthiola Parviflora and Predicting Its Spread in North America”. The Southwestern Naturalist 59 (1). doi:https://doi.org/10.1894/F07-FMO-13.1.
Flora, Southwest. 2020. “Matthiola Parviflora”. https://southwestdesertflora.com/WebsiteFolders/All_Species/Brassicacea….

8. Question 8

No
0
Medium
There is no work that has looked at whether or not this species contributes to the ongoing, novel fire risk in the Sonoran desert. For now, we will answer this question with a no.
Horst, Jonathan L., Sarah Kimball, Judith X. Becerra, Koji Noge, and Lawrence Venable. (2014) 2014. “Documenting the Early Stages of Invasion of Matthiola Parviflora and Predicting Its Spread in North America”. The Southwestern Naturalist 59 (1). doi:https://doi.org/10.1894/F07-FMO-13.1.
Flora, Southwest. 2020. “Matthiola Parviflora”. https://southwestdesertflora.com/WebsiteFolders/All_Species/Brassicacea….

9. Question 9

No
0
Medium
There is no work that has looked at the toxicity of this species and its impact to grazing. For now, we will answer this question with no.
Horst, Jonathan L., Sarah Kimball, Judith X. Becerra, Koji Noge, and Lawrence Venable. (2014) 2014. “Documenting the Early Stages of Invasion of Matthiola Parviflora and Predicting Its Spread in North America”. The Southwestern Naturalist 59 (1). doi:https://doi.org/10.1894/F07-FMO-13.1.
Flora, Southwest. 2020. “Matthiola Parviflora”. https://southwestdesertflora.com/WebsiteFolders/All_Species/Brassicacea….

10. Question 10

No
0
High
Due to the size of the species (growing no larger than 1 to 2 feet) and it consisting of mostly herbaceous material, this species does not inhibit the movement of livestock and humans.
No references cited.

11. Question 11

No
0
Very High
There is no evidence of this plant reproducing in any way except through seed production.
Horst, Jonathan L., Sarah Kimball, Judith X. Becerra, Koji Noge, and Lawrence Venable. (2014) 2014. “Documenting the Early Stages of Invasion of Matthiola Parviflora and Predicting Its Spread in North America”. The Southwestern Naturalist 59 (1). doi:https://doi.org/10.1894/F07-FMO-13.1.
Flora, Southwest. 2020. “Matthiola Parviflora”. https://southwestdesertflora.com/WebsiteFolders/All_Species/Brassicacea….

12. Question 12

No
0
Very High
There is no evidence of this plant reproducing in any way except through seed production.
Horst, Jonathan L., Sarah Kimball, Judith X. Becerra, Koji Noge, and Lawrence Venable. (2014) 2014. “Documenting the Early Stages of Invasion of Matthiola Parviflora and Predicting Its Spread in North America”. The Southwestern Naturalist 59 (1). doi:https://doi.org/10.1894/F07-FMO-13.1.
Flora, Southwest. 2020. “Matthiola Parviflora”. https://southwestdesertflora.com/WebsiteFolders/All_Species/Brassicacea….

13. Question 13

Yes
1
Very High
Yes. This species can produce viable seed and is capable of self-compatible reproduction.
Horst, Jonathan L., Sarah Kimball, Judith X. Becerra, Koji Noge, and Lawrence Venable. (2014) 2014. “Documenting the Early Stages of Invasion of Matthiola Parviflora and Predicting Its Spread in North America”. The Southwestern Naturalist 59 (1). doi:https://doi.org/10.1894/F07-FMO-13.1.
Flora, Southwest. 2020. “Matthiola Parviflora”. https://southwestdesertflora.com/WebsiteFolders/All_Species/Brassicacea….

14. Question 14

No
0
Low
This species has been found to be autogamous with similar seed production either with or without pollinators. However, this is not enough evidence to indicate that this species has the potential to to produce copious, viable seeds each year.
Horst, Jonathan L., Sarah Kimball, Judith X. Becerra, Koji Noge, and Lawrence Venable. (2014) 2014. “Documenting the Early Stages of Invasion of Matthiola Parviflora and Predicting Its Spread in North America”. The Southwestern Naturalist 59 (1). doi:https://doi.org/10.1894/F07-FMO-13.1.
Flora, Southwest. 2020. “Matthiola Parviflora”. https://southwestdesertflora.com/WebsiteFolders/All_Species/Brassicacea….

15. Question 15

No
0
Low
Horst, Jonathan L., Sarah Kimball, Judith X. Becerra, Koji Noge, and Lawrence Venable. (2014) 2014. “Documenting the Early Stages of Invasion of Matthiola Parviflora and Predicting Its Spread in North America”. The Southwestern Naturalist 59 (1). doi:https://doi.org/10.1894/F07-FMO-13.1.
Flora, Southwest. 2020. “Matthiola Parviflora”. https://southwestdesertflora.com/WebsiteFolders/All_Species/Brassicacea….

16. Question 16

Yes
1
Very High
This species is an herbaceous annual, thus able to produce seed within the first year of its life before senescence.
Horst, Jonathan L., Sarah Kimball, Judith X. Becerra, Koji Noge, and Lawrence Venable. (2014) 2014. “Documenting the Early Stages of Invasion of Matthiola Parviflora and Predicting Its Spread in North America”. The Southwestern Naturalist 59 (1). doi:https://doi.org/10.1894/F07-FMO-13.1.
Flora, Southwest. 2020. “Matthiola Parviflora”. https://southwestdesertflora.com/WebsiteFolders/All_Species/Brassicacea….

17. Question 17

Very Low
The phenology of this species has not been studied or researched.
Horst, Jonathan L., Sarah Kimball, Judith X. Becerra, Koji Noge, and Lawrence Venable. (2014) 2014. “Documenting the Early Stages of Invasion of Matthiola Parviflora and Predicting Its Spread in North America”. The Southwestern Naturalist 59 (1). doi:https://doi.org/10.1894/F07-FMO-13.1.
Flora, Southwest. 2020. “Matthiola Parviflora”. https://southwestdesertflora.com/WebsiteFolders/All_Species/Brassicacea….

18. Question 18

Yes
1
Medium
This species invasion history is still largely unknown. At the present, seeds seem to be dispersed by anthropogenic means and not by any other animals. Seeds are elliptic with no or little wing, 1–1.2 by 0.6–0.75 mm and thus have the ability to be tiny enough to stick to fur or feather, or moved during road construction. In addition the silique is horned and can cling to fur, clothing or equipment.
Horst, Jonathan L., Sarah Kimball, Judith X. Becerra, Koji Noge, and Lawrence Venable. (2014) 2014. “Documenting the Early Stages of Invasion of Matthiola Parviflora and Predicting Its Spread in North America”. The Southwestern Naturalist 59 (1). doi:https://doi.org/10.1894/F07-FMO-13.1.
Flora, Southwest. 2020. “Matthiola Parviflora”. https://southwestdesertflora.com/WebsiteFolders/All_Species/Brassicacea….

19. Question 19

No
0
Medium
There is no evidence that this species uses wind or water to disperse.
Horst, Jonathan L., Sarah Kimball, Judith X. Becerra, Koji Noge, and Lawrence Venable. (2014) 2014. “Documenting the Early Stages of Invasion of Matthiola Parviflora and Predicting Its Spread in North America”. The Southwestern Naturalist 59 (1). doi:https://doi.org/10.1894/F07-FMO-13.1.
Flora, Southwest. 2020. “Matthiola Parviflora”. https://southwestdesertflora.com/WebsiteFolders/All_Species/Brassicacea….

20. Question 20

Yes
1
Medium
This species, in its invaded range, inhabits both roadways and undisturbed habitat. Horst et al. 2014 documented that " roadside habitats and also in an undisturbed natural area. Many of the roadside populations inspected in Tucson in spring 2010 were high-density monocultures. It is possible that equipment and other human construction devices help the spread of the species.
Horst, Jonathan L., Sarah Kimball, Judith X. Becerra, Koji Noge, and Lawrence Venable. (2014) 2014. “Documenting the Early Stages of Invasion of Matthiola Parviflora and Predicting Its Spread in North America”. The Southwestern Naturalist 59 (1). doi:https://doi.org/10.1894/F07-FMO-13.1.
Flora, Southwest. 2020. “Matthiola Parviflora”. https://southwestdesertflora.com/WebsiteFolders/All_Species/Brassicacea….

Evaluation Notes

Though this species has spread rapidly throughout southern Arizona, there is almost no research done on it. The only main source of work is Horst et al. 2014 (though a valuable one). I would recommend that more research and work on this species is required before land managers make decisions about the potential threat this species imposes on both conservation and agricultural efforts. 

Total PRE Score

6
19
71

PRE Score Legend

The PRE Score is calculated by adding the point totals for each (answered) question.

< 13 : Low Potential Risk
13 - 15 : Moderate Potential Risk
> 15 : High Potential Risk

Questions Answered Legend

It is important to answer at least 16 questions to consider a PRE Score as "valid".

≥ 16 : Valid (80% or more questions answered)
≤ 15 : Invalid (not enough questions answered)

Evaluation Credits and Citation


Screener:  Anthony Dant

 

Below is a recommend citation when referencing this evaluation in other works:

Dant, Anthony. "Matthiola parviflora -- Arizona" Plant Risk Evaluator (PRE) published 2026-06-10 https://pretool.org/evaluations/5659

 


Please cite this evaluation. We need your support here!

PRE Evaluations take a long time to research, so please credit this site and evaluation appropriately.


Evaluation Reviewers

Bethany DeRango reviewed on 2026-09-28
Umaina Khan reviewed on 2026-07-26
Jutta Burger reviewed on 2026-06-26

 

Associated Project

2023-2025 Western IPM Project

This project intends to support the expanded use of the online PRE tool to more Western States and nations, and to explore the use of the PRE results for each partner region. Along with the direct benefit from the plant assessments, this project will also provide a platform through which to collaborate on a range of efforts related to preventing introduction of invasive plants through horticulture. Each partner can share their expertise on effort such as providing information on safe landscaping alternatives, surveying nurseries for data on what is being sold, comparing species priorities.

 

Associated Organizations, Agencies, and Institutions

California Invasive Plant Council (Cal-IPC)

 

Download PDF


Evaluation PDF... file not found.

Climate Matching PDF


Copyright © 2026 PRETool.org - All rights reserved