Protecting more than 900 taxa, the Endangered Species Act (ESA) is the strongest existing protection for threatened and endangered species in the United States (Oldfield et al., 2019; CBD, 2021). Comparable to the European Union Habitats Directive adopted in 1992 and the Natura 2000 network, these initiatives act as cornerstones for habitat and species conservation in their respective regions (Fois et al., 2018a; Moreno-Saiz et al., 2021). In the U.S., the ESA primarily extends to federal lands (i.e., public and DoD) and does not extend the protections received by other taxa to plants on private lands (Stein & Gravuer, 2008; Negrón-Ortiz, 2022). After 50 years, the ESA continues to play an essential role in preventing extinction for at-risk species as well as offering potential protection for the critical habitat required for their survival. Once sufficient data is provided to warrant a species protection under the ESA, a recovery plan is established using the best available science that outlines the criteria required to down list or “recover” a species, leading to its eventual delisting, the ultimate goal of the ESA. These criteria address factors outlined in the species listing petition, including current and future threats and the minimum required population size for sustaining the species in the wild (USFWS, 1973). Despite the ESAs many strengths, it has been heavily criticized for low rates of recovery, meaning that measurable criteria have not yet been met to avoid species extinction (Heywood, 2019). Only 21 native plants are documented as recovered and removed from the ESA (Haines et al., 2021 and references therein) with this recovery process taking an average of 27 years (Negrón-Ortiz, 2022). The inability of the ESA to meet recovery and delisting goals is frequently traced to chronic inadequate funding and limited baseline data to support species conservation needs (Clark et al., 2002; Negrón-Ortiz, 2014; Gerber, 2016; Malcom, 2021).

Despite a 300% increase in petitioned species over the last ~50 years, funding allocated to the USFWS has diminished or at best, remained stable (Eberhard et al., 2022), creating a backlog and increasing wait time for petitioned and listed species (Puckett et al., 2016; Eberhard et al., 2022). On average, it can take up to 12 years (10 years longer than the maximum length prescribed by law), for a species to move from petition to listing (Puckett et al., 2016). Meanwhile, species are vulnerable to continued extirpation and possible extinction, particularly for species with extremely low population numbers at the time of petitioning (Schwartz, 2008). Recovery progress is positively correlated with funding; however, funding is often skewed toward specific species or taxonomic groups, most notably vertebrates, often overlooking the recovery of the majority of listed endangered species (Negrón-Ortiz, 2014; Haines et al., 2021). Plants lack adequate protections afforded to other taxa (Kennedy, 2008; Gordon et al., 2020) and are underrepresented in terms of allocated funding (Havens et al., 2014), receiving less than 5% of all endangered species funding (Roberson et al., 2020, and references therein).

Many plant species are understudied which is compounded by funding issues. Much of the literature is focused on common, large-ranged plant species that often offer utility to humans (Lughadha et al., 2020 and references therein). In addition to being innately vulnerable, many rare species and their functional traits and interactions within their environments are undescribed or poorly known causing their risk of extinction to be potentially underestimated (Pimm et al., 2014; Fois et al., 2021). A lack of up-to-date research means that listing is prolonged due to insufficient data, and recovery efforts are often outlined and prioritized based on outdated datasets and information, which further perpetuates mismanagement and hinders plant protection and conservation (Estill and Cruzan, 1999; Le Roux et al., 2019; Molano-Flores and Coons, 2019). Despite most species requiring long periods to reach recovery and delisting, successful recovery has been the result of appropriate population protection, ensuring partnerships and private landowner engagement, and restoration and threat management (Haines et al., 2021). Recovery goals can be achieved for some of our most at-risk species if up-to-date data are available.

In this paper, we review the timeline of recovery goals for M. alba (a species listed for over 30 years), present a synopsis of recent research findings (i.e., species distribution models, habitat associations, reproductive ecology), and identify achievements as well as persistent obstacles to recovery and delisting. Our goal is to answer the following question: is the ESA living to its full potential when it comes to the conservation of M. alba and other rare plants?

Basic requirements for species status assessment and recovery planning include documentation of three aspects of a species’ ecology including the following: 1) current abundance and distribution, 2) potential natural causes of variation across populations, and 3) life history strategies that most impact population dynamics (Schemske et al., 1994; Havens et al., 2014). Ongoing monitoring and published research have provided valuable information relevant to these requirements, however the region where M. alba is found has experienced significant change since the completion of this work over 20 years ago; particularly related to land use, management, and development. A reassessment of the species’ status in the context of present conditions is critical for assessing appropriate recovery goals for ongoing protection of the species. In this section, we summarize the results of three objectives and how they relate and contribute to the recovery actions ( Table 2 ) of the species:

Objective 1 : Evaluate the accuracy and utility of species distribution models to locate suitable habitat and new populations of M. alba. – Recovery Actions 1.1, 3.1, and 5.

Objective 2 : Assess the abundance, distribution, and habitat associations of M. alba populations by conducting field surveys within its prospective range. – Recovery Actions 1.1, 3.1, and 3.2.

Objective 3 : Reassess the reproductive ecology of M. alba and evaluate the implications for conservation of the species. – Recovery Actions 1.2 and 5.

Cooperative Endangered Species Conservation Fund or “Section 6” funds in collaboration with the USFWS and the Florida Forest Service, provided funding support for data collection and analyses associated with M. alba recovery actions. Data sets were generated during the flowering and fruiting season (May – September) of 2019 and 2021.

In the 30 years since listing, there have been major advances in our knowledge of the basic ecology and reproductive biology of M. alba that have led to improved monitoring and management where populations persist, undoubtedly facilitating in the conservation of associate species as well. Thanks to the tireless advocacy of USFWS biologists and their regional conservation partners (e.g., Florida Forest Service), this species has received renewed attention and a call to action after years of stagnation on the Endangered Species list. Our contribution to several recovery actions played a role in updating data critical to the prioritization of future conservation and recovery efforts for the species. While M. alba is presented here as a case-study, this strategy is transferable for other rare species and provides an efficient framework to rapidly assess species status, ensuring that limited conservation resources are employed to their full potential.

Our research confirmed that based on the best available data, there is high conservation and reintroduction potential for M. alba as the species shows high ex situ germination rates and stable population numbers throughout its known range. By confirming the status of historic occurrence records, we have documented a likely shrink in species distribution outside the confines of protected areas while also identifying populations that will likely experience increased decline and extirpation if action is not taken to create partnerships or conservation easements. This work has made novel contributions, such as the discovery of six additional records for M. alba including one outside of conservation lands and has documented potential herbivore pressure from a previously unrecorded seed predator for M. alba. Locating areas for potential reintroduction and actively attempting such introduction will prioritize actions to increase the total number of protected populations that are required to delist the species.

Despite these contributions, recovery is not currently sufficient to warrant the delisting of the species. The most recent 5-year review (Negrón-Ortiz, 2020) compiled results of all research conducted to date, including research conducted by our team. Recovery achievements are at a level 2 with about 26-50% recovery objectives having been achieved; a number unchanged since the 2009 5-year review for the species (Negrón-Ortiz, 2009; Negrón-Ortiz, 2020). The USFWS is doing the best work possible with the available resources they have by facilitating partnerships to fill data gaps that inhibit successful conservation. Unless more resources are allocated to the conservation of the species by the next 5-year review in 2025, it is unlikely that additional recovery goals will be met for the species, and it will remain at its present status.

The persistent challenges faced by the agency to progress species recovery and delisting are outlined in the recent 5-year review (Negrón-Ortiz, 2020), focusing heavily on the difficult task of expanding conservation and improving management within private lands. Despite the overall stability of population numbers over time, there are valid concerns that the few remaining areas harboring populations face increased threats. Almost 70% of all documented occurrences for M. alba are located within ANF, highlighting the destructive potential of stochastic events, both environmental (i.e., devastating impacts of hurricane Michael) and genetic (i.e., further distance between and fragmentation of natural populations). It is of the utmost importance that these lands are protected in perpetuity, but moreover, that new populations are identified and protected as soon as possible. In addition, reintroduction in novel territory that may be habitable for the species in future conditions should be explored (Volis, 2019). Because most populations are protected on public lands, critical habitat was never designated for the species (USFWS, 1992) and damaging practices like slash-and-burn agriculture and poor management of private timberlands and cattle farms (as well as rights-of-ways) have led to the destruction of M. alba habitat and extirpation of populations. Until the minimum of 15 distinct populations are protected, the species must remain under protection, and even then, protection in perpetuity is necessary for species survival due to its inherently narrow range. Future efforts should focus on engagement with private landowners to coordinate protections in a diverse suite of habitats and the implementation of meaningful incentive programs are essential to engage landowners in prescribed burning and sustainable management.

These barriers are not unique to M. alba and for most species, many recovery actions remain unaccomplished or in limbo (Lundquist et al., 2002). Recovery expenditures do not match the need or priorities set in place by recovery plans (Schwartz, 2008) and the development and application of a resource allocation framework (Gerber et al., 2018) is essential to continued success. The utilization of species status assessments in recent years has been an improvement for filling data gaps for listed or petitioned species, helping to expedite a typically arduous timeframe and needs to be applied broadly going forward (Noss et al., 2021). However, as research can be slow to implement once a species is listed, it is important not just to engage a diverse array of institutions and partners to conduct research on listed species, but also incentivize research of at-risk or even currently widespread species so that in the event of petitioning, some information is already in place to assist with these decisions (Molano-Flores, 2021). New funding sources such as the Recovering America’s Wildlife Act (RAWA, if approved by Congress) or other avenues of conservation funding could accelerate and fuel this progress.

Plants need priority in funding, listing, and recovery as the foundation of the planet’s biodiverse ecosystems. It is an unignorable fact that the recovery of other wildlife hinges on the success of plant recovery efforts and habitat preservation. In the face of recent reports of devastating habitat loss and increased extinction risk, effective legislation and conservation programs have failed to reflect this need (Pimm et al., 2014; Lughadha et al., 2020). At present, the Endangered Species Act is not living to its full potential in protecting plant species. An increase and more diverse range of funding to the USFWS and their partners is critical to the future success of the ESA but importantly, ensuring that increased funds are allocated in a way that support the mission of efficient listing, recovery planning, and ultimately, delisting species. Fortunately, with the dedicated work of state/federal agencies, and non-government organizations, species like M. alba have some protection in the face of future uncertainty. Our ability to protect plants in the face of current and future change is contingent upon prompt and effective protection for plants and their ecosystems. With limited resources devoted to plant conservation efforts, researchers need efficient methods for rapidly assessing a species’ status, learning about aspects of ecology, distribution, habitat requirements, and potential for reintroduction. Together these results can help those working with species at risk make more informed decisions and further our knowledge of the ecology of rare plants and their environments.

The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.

SJ and BM-F conceived conceptual framework presented in the manuscript. SJ wrote the first draft of the manuscript. All authors contributed to the article and approved the submitted version.