Plantago altissima

Iamonico, Duilio, Fortini, Paola & Pietro, Romeo Di, 2019, Typification of the Linnaean names Plantago afra, P. altissima, and P. lagopus (Plantago subg. Psyllium, Plantaginaceae), Phytotaxa 405 (4), pp. 210-214 : 211-212

Plantago altissima

Linnaeus (1762: 164) provided a diagnosis for Plantago altissima (“ PLANTAGO foliis lanceolatis quinquenerviis dentatis glabris, scapo subangulato, spica oblong-cylindrica”), and cited one synonym (“ Plantago montana , craffo, glabro, canaliculato tenuioreque folio, profundissime radicata”) from Tilli (1723: 136). The provenance (“ Habitat in Italia ”) was also provided and, according to Tilli (l.c.), the locus classicus was “ In collibus Imprunetae ” which refers to the municipality currently know as Impruneta (Province of Florence, Tuscany region, Central Italy).

There is one specimens at LINN (no. 144.10) bearing one leaf and a part of a stem with a terminal inflorescence. The original Linnaean annotation “ HU [Hortus Upsaliensis] hybrida altissima ” also occurs on the sheet (bottom-centre). This specimen is part of the original material used by Linnaeus to describe Plantago altissima . Since the LINN-144.10 appears to be the only original extant material (see also Jarvis 2007: 748), and its morphology matches the diagnosis, we here designate it as lectotype.

According to the current treatment of Plantago (see e.g., Moore 1976, Pignatti 1982, Pedrol 2008), LINN-144.31 is comprised in the collective group of P. lanceolata sensu Pignatti (1982) , which includes P. lanceolata L., P. altissima L., and P. argentea Chaix. Also Moore (1976) in Flora Europea considered these three species as being very similar from a morphological viewpoint. On the basis of personal observations on both living populations and dried specimens, we cannot do anything but confirm this similarity, and the difficulty in finding diagnostic characters useful for the clear identification of these three species. The taxonomical literature reports some morphological differences ( Table 1). Unfortunately, no comprehensive works including molecular data of all these three species appears to be published. Most of the phylogenetic works on Plantago includes the widespread P. lanceolata (see Rønsted et al. 2002 and literature therein), while few papers reports P. argentea (see e.g., Li et al. 2014). We have not been able to trace paper which includes molecular data about P. altissima . Also caryoplogical data was mostly published for P. lanceolata (e.g., Bartolo et al. 1980, Dmitrieva & Parfenov 1985, Druskovic & Lovka 1995, Peruzzi 2003, Dhar 2006), while few paper regards P. argentea (see e.g., Monserrat Marti 1981, Druskovic & Lovka 1995).

Because of the lectotype exhibits a 2.5 cm wide green leaf we can easily exclude Plantago argentea as a possible reference. More difficult is to choose between P. lanceolata and P. altissima , the most reliable diagnostic characters being those concerning root and rhizome traits (lacking in the lectotype). However, the 7–8 ribs occurring on the stem and the about 6 mm long bracts allowed us to identify this specimen as P. altissima .