| Author | Coulter & Rose | |
| Distribution | Scattered over much of the Coastal Plain, though mainly the eastern region; scattered in the western half of the Piedmont and in the Mountains. As this taxon is often considered as part of C. maculata, it is possible that a number of SERNEC specimens in herbaria other than NCU for C. maculata could possibly refer to this taxon instead. As a result, few biologists are likely aware of this species and presumably would overlook it as C. maculata.
This taxon ranges from southeastern VA south to FL, and west to TX, and of course farther southward into MX. | |
| Abundance | Poorly known at the present time, and not ranked by the NCNHP. The spread of county records suggest to the website editors a State Rank of S3? at the present time. It does not seem to necessitate being placed on a Watch List, with at least 30 counties documented for it. As NatureServe does not recognize this entity, the editors suggest a Global Rank of G5?. | |
| Habitat | This is a wetland species that often grows in shallow water, along marshy shores, or in floating mats of vegetation along rivers or in swamps. | |
| Phenology | Blooms from May to August, and fruits from July to September. | |
| Identification | This is a quite stout species, growing to 5-6 feet tall, more robust than is C. maculata. Like that species, it has scattered alternate leaves that are very large and triangular, but highly dissected into double- or triple-pinnate leaf segments. The key separation feature is that the leaflets are ovate in shape rather than lanceolate (in C. maculata), and thus the leaflets average 1.5-2 inches wide as opposed to mainly less than 1-inch wide in the common species. Both species have several large umbels of flowers, composed of numerous umbellets, with flowers being white. There are also differences in the shape of the seeds of these two species, with this one being constricted at the commissure, as opposed to not constricted in C. maculata. For most biologists, the shape and width of the leaflets should be somewhat obvious in the field. | |
| Taxonomic Comments | See Distribution. Though RAB (1968) did consider it as a species, it stated "A doubtful species, only weakly differentiated" from C. maculata in the Carolinas. Some references, such as NatureServe, do not recognize this entity even as a variety.
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| Other Common Name(s) | Mexican Water-hemlock | |
| State Rank | [S3?] | |
| Global Rank | GNA [G5?] | |
| State Status | | |
| US Status | | |
| USACE-agcp | | |
| USACE-emp | | |
