| Classification | Asteraceae: Cirsium |
| Classification 1 | Asteraceae: Cnicus |
| Harvard University Herbaria Barcode(s) | 00139021 |
| Type Status | Probable Syntype |
| Collector | G. Thurber |
| Collector number | 433 |
| Country | Mexico |
| State | Sonora |
| Geography | North America: North America (CA, US, MX) (Region): Mexico: Sonora: Fronteras |
| Locality | Fronteras |
| Date Collected | 1851-06-** |
| GUID | http://purl.oclc.org/net/edu.harvard.huh/guid/uuid/13d2fc33-5cd3-4708-8c19-41d820035af3 |
| Harvard University Herbaria Barcode | 00139021 |
| Herbarium | GH |
| Previous ownership | ex Coll. Geo. Thurber |
| Family | Asteraceae |
| Determination | Cirsium undulatum (Nuttall) Sprengel |
| Determination Remarks | [is label name] |
| Family | Asteraceae |
| Determination | Cirsium undulatum var. megacephalum (A. Gray) Fernald |
| Determined by | B.L. Robinson |
| Date Determined | 1911 |
| Family | Asteraceae |
| Determination | Cirsium undulatum (Nuttall) Sprengel |
| Determined by | G.B. Ownbey & Y. Hsi |
| Date Determined | 1960 |
| Family | Asteraceae |
| Determination | Cirsium undulatum (Nuttall) Sprengel |
| Determined by | G. Nesom |
| Date Determined | 1988 |
| Determination Remarks | [is Current name] |
| Family | Asteraceae |
| Type Status | Probable Syntype |
| Probable Syntype of | Cnicus undulatus var. megacephalus A. Gray |
| Verified by | G. Nesom |
| Date Determined | 1988 |
| Taxon Reference | (for Cnicus undulatus var. megacephalus A. Gray) Proc. Amer. Acad. Arts 1875. 10: 42. |
| Sex | not determined |
| Phenology | Fruit |
| Preparation Type | Sheet |
| Preparation Method | Pressed |
