Notes on nomenclature and typification of Heteropogon fischerianus and H. contortus var. distichus (Poaceae)

1Central National Herbarium, Botanical Survey of India, P.O. Botanic Garden, Howrah, West Bengal – 711 103, India. 24, Botanical Garden Lane, Howrah, West Bengal – 711 103, India. 323F, Fern Road, Kolkata, West Bengal – 700 019, India. *Email: avibsi@rediffmail.com RHEEDEA Journal of the Indian Association for Angiosperm Taxonomy Vol. 30(2): 270–277 (2020) ISSN: 0971-2313 (Print edition) ISSN: 2582-2438 (Online edition) https://dx.doi.org/10.22244/rheedea.2020.30.02.02


Introduction
The genus Heteropogon Pers. includes six species distributed from Europe to tropical and subtropical regions of the World and all of the species are also known from India (Clayton et al., 2020;Drisya & Pradeep, 2020 (Kress et al., 2003). Further, Clayton et al. (2020) treated H. polystachyus as a heterotypic synonym of H. contortus which has a wide distribution. Therefore, in India the only endemic species in the genus is H. fischerianus which is confined to Andhra Pradesh, Karnataka, Kerala, Tamil Nadu and Telangana . Deshpande (1988)  A. Barber" in the protologue. He also stated "This very distinct and remarkable species of Heteropogon was considered by Fischer to be merely a variety of Heteropogon contortus (Linn.) P.Beauv. to which he gave the name var. distichus C.E.C.Fischer. The habit of the species is, however, so unique and, moreover, the spikelets smaller than those of Heteropogon contortus, that there is no doubt that this plant merits specific rank". Although Bor (1951) could have adopted the epithet 'distichus' used at varietal rank by Fischer, he had no obligation either to adopt Fischer's epithet or to typify his name by an element available to Fischer according to Art. 11.2 (Turland et al., 2018); instead of adopting 'distichus' he commemorated Fischer in the name of his new species, but he did in fact typify it by a specimen of one of the collections (2025 at K) cited by Fischer. Bor (1951) had three options when publishing this new species: 1). Describing the species as new (Art. 6.9), in which case it would be normal, but not obligatory, to adopt a different epithet from that of the variety. As such its publication would require to satisfy all the requirements for valid publication of the name of a new species (see esp. Art. 38-40), including, after 1957, indication of type; 2). Publish a new combination based on Heteropogon contortus var. distichus (Art. 6.10). This would require the species to be called "H. distichus (C.E.C.Fisch.) Bor" and would necessitate to satisfy the requirements for valid publication of the name of a new combination (see esp. Art. 41). It would necessarily be typified by the type of its basionym (the varietal name) (Art. 7.3) regardless of the elements to which the later author applied it; 3). Publish a replacement name ("avowed substitute") with H. contortus var.
distichus as its replaced synonym (Art. 6.11); this would necessarily have a different epithet from that of the variety but would necessarily be typified by the type of its replaced synonym (the varietal name) (Art. 7.3) regardless of the elements to which the later author applied it. It would also have to meet the requirements of Art. 41.
Among the above three options, the first option was chosen by Bor (1951). Moreover, Bor (1951) included "all [the] syntypes under Art. 9.6" of H. contortus var. distichus, but no type of H. contortus var. distichus C.E.C.Fisch. had been designated in 1951. As Bor (1951) had published a new species and "a name has no priority outside the rank at which it is published" (Art. 11.2), the name was validly published as a new species as he provided a Latin diagnosis (and description). He also indicated the type although that only became mandatory from 1958 onwards. If Bor had been publishing the name of a new variety and used the epithet 'fischerianus', that name would have been superfluous and illegitimate according to Art. 52.2(a), but, for a species name, H. contortus var.
distichus was not "a name ... of which the epithet ought to have been adopted [by Bor], under the rules" (Art. 52.1) (Turland et al., 2018).

Notes on typification
There are four specimens of Bourne 2025, one each at CAL, G, K, US; three specimens of Bourne 2026 are at CAL, K, MH (one each); two specimens of Barber 3719 are at FRC, MH (one each). As Bor (1951) cited only Bourne 2025 (K) as type in the protologue and there is a single specimen belonging to this collection at K, Bourne 2025 (K) is the holotype of Heteropogon fischerianus and duplicates of this number are isotypes while the remaining cited specimens are paratypes of this name. Siddabathula et al. (2020)  Bourne 2026 (K000245942) as lectotype by Siddabathula et al. (2020). Though Deshpande (1988)