Acanthocereus tetragonus (L.) Hummelinck

Cereus vasmerae M.J. Young, Familiar Lessons Bot. 276. 1873 (“ Vasmerii ”). TYPE: U.S.A. Texas.Webb Co.:Laredo,1906, J.N. Rose & J.S.Rose s.n. ( NEOTYPE, designated here: US [ US 00048387]-excluding seeds in packet!).

Acanthocereus tetragonus (L.) Hummelinck View in CoL , Succulenta ( Netherlands) 20:165. 1938.

Cereus vasmerae is the only new species that Young (1873) appears to have intentionally published. Its type locality is stated to be “On hills near La Grange [Fayette Co., Texas]” and the species also was said to have been “introduced into gardens by Mrs. T.W. House.” Mrs. House or Mary Elizabeth House (née Shearn) (1822– 1870) was the wife of Thomas William House (1814–1880), a financially successful Houston merchant and entrepreneur ( Beazley 2021). Presumably the gardens noted by Young (1873) were those of their social circle in Houston.

It is not altogether clear that Young’s new species was based on herbarium material and no original material of C. vasmerae is known. The neotype consists of flowers and the remnants of a fruit. The specimen appears to have been prepared from a cultivated plant (“06.1012”) from which seeds were acquired in September 1911. A separate sheet ( US [ US 00048384]!) consists of seedlings of “06.1012” gathered in 1911. The seeds in the packet of the neotype and the separately-mounted seedlings cannot be considered part of the type gathering ( Turland et al. 2018; Art. 8.2) even though they are very likely genetically identical to the neotype.

The etymology of the species epithet was not fully explained by Young (1873). She simply stated that Cereus vasmerae was “named for Mrs. Vasmer,” who probably was Elisabeth Holt Vasmer (née Stanley) (1835– 1907) of Houston, the widow of a Dr. Ernest Henry Vasmer (1829–1865).