# New Research Paper: "Poa annua: An annual species?"



## Idaho Turf (8 mo ago)

"Poa annua: An annual species?"

This new research paper (9/9/22) finds that poa annua is a perennial grassy weed (not an annual) and it perishes largely from fungal infections which may be exacerbated by cultural conditions. I don't know if this will have any bearing on suppression, but I found it interesting.

*Authors:* Devon E. Carroll, Brandon J. Horvath, Michael Prorock, Robert N. Trigiano, Avat Shekoofa, Thomas C. Mueller, James T. Brosnan 
*Published:* September 9, 2022

*Conclusions*
Results of these experiments suggest P. annua perishes from fungal infection, which may be exacerbated by environmental and anthropogenic stresses during summer months. Poa annua seems to persist unless environmental conditions are unfavorable, often presenting as a polycarpic plant rather than succumbing to programmed senescence. This environmentally driven response is similar to that of other perennial C3 grass species such as Kentucky bluegrass or tall fescue. On the contrary, annual species are monocarpic plants senescing after a single reproductive cycle regardless of environment. *Our results show that P. annua does not meet the definition of an annual species. Observations made in this study and via an exhaustive review of peer-reviewed literature present little evidence supporting an inherently annual life cycle in P. annua.*

We contend the epithet “annua” is a misnomer according to its current interpretation. Although “annual” can be associated with life cycle, “occurring once every year” is also a definition of the word. Thus, the species epithet “annua” may have been awarded to P. annua to mark a yearly observation such as growth at the same location or yearly inflorescence production rather than of an annual life cycle.

Early taxonomic descriptions of P. annua provide no evidence of life cycle study at the time of naming, indicating the species name has been misconstrued in modern times. The shift in present understanding of P. annua as a perennial rather than the long purported annual species has major implications for plant management. Therefore, a more appropriate and descriptive name may be P. typica or P. vulgari, meaning ‘typical’ and ‘common’ in Latin, respectively. These epithets preclude misinformation surrounding life cycle and indicate the species prevalence given that P. annua is found on all seven continents in a myriad of climates.


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## 440mag (Jan 29, 2018)

@Idaho Turf , Thanks for posting this up; I’m confident I’d not seen it otherwise!


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