| Author | Chapman | |
| Distribution | Limited to the southern Coastal Plain, in two discrete regions -- the Sandhills (Moore, Hoke, and Cumberland counties) and the southeastern portion (Onslow, Pender, Brunswick, and Columbus counties). Specimens for Hoke and Cumberland counties are at the herbarium on Fort Bragg and correctly identified (fide BA Sorrie).
This is a Coastal Plain species found from southern NC south to northern FL and west to eastern TX. | |
| Abundance | Very rare, and apparently declining. The NC NHP database has just four records, but one is historical. The SERNEC database contains just three specimens. Thus, the NC NHP State Rank of S2 is incorrect and should clearly be S1, as this website recommends. Though only considered as State Significantly Rare, it probably should be given legal State protection as Threatened or Endangered. | |
| Habitat | It is found in wet pine savannas, but in the Sandhills it presumably occurs in seepages that are frequently burned to mimic a savanna. |
| Phenology | Blooms mostly in April, and fruits in May. As with other savanna species, a spring fire will cause the species to bloom later in the season. | |
| Identification | This star-grass (Hypoxis) is similar to the others, with narrow basal leaves and 1 or 2 star-shaped yellow flowers. However, this species has numerous stiff bristles (almost spine-like) at the base of the plant, and the narrow leaves are quite stiff/rigid. Other star-grasses have rather flexible leaves. Weakley (2018) gives several additional characters that separate it from H. sessilis and H. wrightii. Hypoxis rigida has anthers more than 2 mm long and tepals longer than the pedicels, whereas the other two have anthers less than 2 mm long and the tepals shorter than the pedicels. You likely will have some difficulty identifying this species in the field, unless you get on hands and knees, perhaps with a hand lens and a ruler, or make a collection to measure later. Though the rather stiff leaves should be a clue, you may well want to rely on additional characters to identify this rare species. And, note that most of the well-managed savannas in the coastal counties lack records for it. | |
| Taxonomic Comments | None
| |
| Other Common Name(s) | Savanna Star-grass, Stiffleaf Star-grass | |
| State Rank | S2 [S1] | |
| Global Rank | G4 | |
| State Status | SR-P | |
| US Status | | |
| USACE-agcp | FACW link |
| USACE-emp | FACW link |
