Knowledge of regional Texas floras is crucial for understanding species distributions. In addition, such knowledge is important for the management and preservation of individual plant species and ecosystems across the state. Floristic data for Mills and San Saba counties (Figure 1) is poorly known. Having an updated list of vascular plants is important for documenting changes in species distributions over time. This knowledge can be used in management plans for conserving endangered species, documenting the spread of invasive plants, and to improve the use of native species in restoration projects. While conducting community ecology studies at Colorado Bend State Park, Timberlake Biological Field Station, and near the town of Regency, Texas (Figure 1), voucher specimens were collected and included 20 species that had not been documented for Mills or San Saba counties nor included in other field investigations over the last five years (Gamez et al. 2016; Sheik & Nelson 2019).

Figure 1.

Map of Texas showing the location of Mills and San Saba counties and sampling sites.

Figure 1.

Map of Texas showing the location of Mills and San Saba counties and sampling sites.

Close modal

Vascular plant specimens from the Tarleton State University Herbarium were examined from Mills and San Saba counties. Each specimen was classified as native, endemic, or introduced using Shinners and Mahler’s Illustrated Flora of North Central Texas (Diggs et al. 1999). Plants were compared to those which occur on the Texas state-listed noxious weeds list (USDA 2019), state threatened and endangered plant species list (TPWD 2010), and rare plants of Texas (Poole et al. 2007). Distributions of taxa were compared to those published in the Atlas of the Vascular Plants of Texas (Turner et al. 2003a, 2003b). Based on data from the atlas, we categorized our specimens as documenting major range extensions (taxa collected in Mills and San Saba counties but not known from adjacent counties) or county records (taxa that have been reported from adjacent counties).

Results & Discussion.–Twenty species representing 15 families were identified as new records from Mills and San Saba counties (Table 1). Sixteen taxa are native and four are introduced species. No species were found that were included on the state noxious weeds list (USDA 2019). There were no rare (Poole et al. 2007), threatened, endangered, or state-listed plant species (TPWD 2010).

Table 1

List of collected species (common names in parenthesis) in their respective counties including existing records from bordering counties (Turner et al. 2003a; 2003b). Counties include Brown (Br), San Saba (SS), Lampasas (La), Comanche (C), Hamilton (H), Burnet (Bu), Llano (LL), McCulloch (Mc) and Mills (M). Classification as Native (N), endemic (E), or introduced (I) as well as Tarleton State University Herbarium (TAC) accession numbers for each. Major Range Extensions are abbreviated as MRE representing no surrounding county records.

List of collected species (common names in parenthesis) in their respective counties including existing records from bordering counties (Turner et al. 2003a; 2003b). Counties include Brown (Br), San Saba (SS), Lampasas (La), Comanche (C), Hamilton (H), Burnet (Bu), Llano (LL), McCulloch (Mc) and Mills (M). Classification as Native (N), endemic (E), or introduced (I) as well as Tarleton State University Herbarium (TAC) accession numbers for each. Major Range Extensions are abbreviated as MRE representing no surrounding county records.
List of collected species (common names in parenthesis) in their respective counties including existing records from bordering counties (Turner et al. 2003a; 2003b). Counties include Brown (Br), San Saba (SS), Lampasas (La), Comanche (C), Hamilton (H), Burnet (Bu), Llano (LL), McCulloch (Mc) and Mills (M). Classification as Native (N), endemic (E), or introduced (I) as well as Tarleton State University Herbarium (TAC) accession numbers for each. Major Range Extensions are abbreviated as MRE representing no surrounding county records.

Conium maculatum L. (poison hemlock) is an introduced species from Asia and Europe that is extremely poisonous (Diggs et al. 1999), which is mainly known from south and east of San Saba County (Turner et al. 2003a). Our specimen extends its range north and west with a collection from Colorado Bend State Park (CBSP).

Cladium mariscus (L.) Pohl subsp. jamaicense (Crantz) Kük. (Jamaican saw-grass) is a native species (Diggs et al. 1999), previously known only from south and east of San Saba County (Turner et al. 2003b). Our specimen extends its range north and west with a collection from CBSP.

Ranunculus abortivus L. (little-leaf buttercup) is a native buttercup (Diggs et al. 1999), which is found north and east of San Saba County (Turner et al. 2003b). A collection from CBSP extends its range south and west.

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