Commelina pallida Humb. & Bonpl. ex Willdenow (1816

Hassemer, Gustavo, 2020, Further cleaning of the name pool in the New World Commelina (Commelinaceae), and notes on the African C. aquatica, Phytotaxa 435 (2), pp. 101-132 : 110-115

1.8. Commelina pallida Humb. & Bonpl. ex Willdenow (1816 : t. 87)

Type: — GERMANY. Cultivated at the Berlin Botanic Garden, from seeds most likely originated in Mexico (see discussion below), s.d., Anonymous s.n. (lectotype [designated here] B barcode BW 01051010! [ Figure 12 in Hassemer 2018a], plant on the right side of the sheet).

Notes: —Previously, in Hassemer (2018a: 39), I proposed to designate the “specimen” B barcode BW 01051010 as lectotype for C. pallida . However, with further study of the complicated circumstances associated with this name I came to realise that this sheet in fact includes two distinct specimens. One of them, the plant on the left side of the sheet, appears to have been collected by Alexander von Humboldt and Aimé Bonpland somewhere in the Americas, most likely in Mexico, considering the information provided in von Humboldt et al. (1816: 259): “ Crescit in alta planitie Mexicana inter Queretaro et San Juan del Rio, alt. 950—1100 hexap. ”. The plant on the right side of the sheet is indicated to have been cultivated in the Berlin Botanic Garden. Therefore, the sheet comprises two distinct gatherings, and for this reason my previous typification (in Hassemer 2018a: 39) was not effective.

The folder in which the sheet B barcode BW 01051010 in contained, i.e. B barcode BW 01051000, is annotated “ Habitat in America meridionali ”, probably by Willdenow himself. This apparently incorrect information on provenance nevertheless matches that which was provided in the protologue ( Willdenow 1816: t. 87). Furthermore, in the protologue, Willdenow stated “Colitur aestate sub dio, aservatur hyeme in caldario. Floret aestate, seminaque perficit. Propagatur seminibus et divisione radicis”, which attests that the species was being cultivated at the Berlin Botanic Garden. For this reason, I designate here the plant on the right side of the sheet B barcode BW 01051010 as lectotype.

It is important to note that Espejo-Serna & López-Ferrari (1995: 8) did not (inadvertently) lectotypify the name C. pallida , because the specimen they cited as “ TIPO ”, i.e. “ Querétaro, crescit in alta planitie mexicana inter Querétaro et San Juan del Río, alt 950-1100 hex [1737-2015 m]. Floret Augusto, [VIII-1803], A. Humboldt & A. Bonpland (P-Bonpl.)” (referring to the specimen P-00669531), cannot be considered original material for this name, as there is no evidence that Willdenow ever saw this specimen. This is further corroborated by the match of the (apparently incorrect) information on provenance provided in the protologue of C. pallida and annotated on the folder ( B barcode BW01051000) containing the lectotype.

I also need to remark that the protologue of C. pallida informs the colour of the petals of the species as pallid blue (“pallide coerulea”), which was later confirmed in von Humboldt et al. (1816: 259): “pallide caerulea”. Previously, in Hassemer (2018a: 39), I mentioned that the species has white flowers, which was a mistake.

Hunt (1994: 173) stated that C. pallida and C. texcocana Matuda are not synonymous, with which I agree. Based on comparison of the morphology of type specimens, I am convinced that the most similar species to C. pallida is C. bravoa (see above). The available records indicate that C. pallida is endemic to Mexico. Further study is necessary to ascertain the circumscription of C. pallida and clarify the distribution (and consequently the conservation status) of this species. Unfortunately, it is possible that the species is no longer extant, as all known gatherings were most likely made during the nineteenth century.

Specimens studied: — GERMANY. Cultivated at the Berlin Botanic Garden, s.d., Anonymous s.n. ( B barcode BW 01051010 [plant on the right side of the sheet]). MEXICO. S.l., s.d., Anonymous s.n. (G-00489184); S.l., s.d., Anonymous s.n. (G-00489187); Querétaro state: s.d., F. W. H. A. von Humboldt & A. J. A. Bonpland s.n. ( B barcode BW 01051010 [plant on the left side of the sheet], P-00669531).

Figures

FIGURE 12. Lectotype of Commelina diffusa var. cordispatha (O. Rohweder 882, HBG-514345). Copyright: Universität Hamburg.