Porpax dalzellii (Hook.) Nandikar & Bramhad., 2023

Porpax dalzellii (Hook.) Nandikar & Bramhad. , comb. nov. Fig. 3b View Fig

An Indian endemic and epiphytic orchid, Porpax dalzellii , can be recognized by its reticulately veined pseudobulbs, secund flowers, sepals, and petals with glandular margins (sparse at apex, dense at base) and an erose lip. The species appears to have a wider distribution ( Maharashtra, Karnataka, Kerala, and Tamil Nadu) compared to other Porpax species in peninsular India . Porpax dalzellii was based on Dendrobium dalzellii , which was described by Dalzell on the basis of an orchid he had collected in the woods at Ram Ghat [ Maharashtra]. He had proposed the name “ Dendrobium fimbriatum ” for it but, presumably in editing Dalzell’s MS, Hooker drew his attention to the existing D. fimbriatum ( Hooker, 1823) and proposed instead the name D. dalzellii . As only the name (not the description) was ascribed by Hooker, the name must be attributed to “Dalzell ex Hook.” or just to “Dalzell” according to Art. 46.5 of the ICN ( Turland et al., 2018).

Lindley (1858) transferred Dendrobium dalzellii to Eria , citing Dendrobium filiforme Wight (Icon. Pl. Ind. Orient. 5(1): 5, t. 1642. 1851) in the synonymy. This makes the name E. dalzellii superfluous; however, it has been widely adopted for over a century ( Hooker, 1890; Gammie, 1906; Cooke, 1908; Blatter & McCann, 1931; Saldanha, 1976; Joseph & Ansari, 1989; Lakshminarsimhan, 1996; Santapau & Kapadia, 1966; Pradhan, 1979; Abraham & Vatsala, 1981; Kumar & Manilal, 1994; Noltie, 2005; Mulgaonkar & Dabhade, 2005).

Dendrobium filiforme Wight (1851) View in CoL was found to be based on collections of Wight (Nilgiris and Iyamally Hills) and Law ( Bombay? Belgaum?), which included two different species, viz. Eria nana A.Rich. View in CoL and Dendrobium microchilos Dalzell View in CoL ( Hooker, 1890; Noltie, 2005). In fact, Wight ( l.c.) in the protologue of D. filiforme View in CoL also noted variation within the species commenting that “the plate exhibits three forms, all more or less differing but still evidently the same species”. We found that the description of D. filiforme View in CoL and the original material contain a mixture of three different taxa: 1. Eria nana View in CoL (‘Icones.’ No. 1642: the right bottom figure is based on his own collection from ‘172 Nilgiris’, a left bottom specimen at K [K000883999]) with a solitary scape and sub-sessile few large flowers, and a distinctly clawed lip; 2. Dendrobium microchilos View in CoL (‘Icones.’ No. 1642: top bottom figure appears to be identical with Law’s collection from Bombay? or Belgaum at K [K000827404]) and can be characterized by filiform scapes, alternate, whorled to semi-secund flowers, and a lip with hyaline margins; 3. Dendrobium dalzellii View in CoL (‘Icones,’ No. 1642: middle figure apparently matches with his own collection from Pulney Hills? at K [K000357712]), and is unique by its much smaller habit, distinctly secund flowers, and a serrulate lip.

In the last few decades, Dendrobium filiforme View in CoL has been presented as Eria filiformis (Wight) Rchb.f. View in CoL , Conchidium filiforme (Wight) Rauschert View in CoL , Porpax filiformis (Wight) Schuit., Y.P.Ng & H.A.Pedersen , and also appeared in regional literature ( Agrawala, 2009; Nayar et al., 2014; Singh et al., 2015; Jalal, 2018). Nevertheless, the authors believe that Dendrobium filiforme View in CoL long remained a nomenclatural problem as it was based on discordant elements – a reason for rejection ( Stafleu et al., 1972), and this is a possible reason for the name being abandoned by several workers.

The epithet ‘ filiforme’, perhaps denoting ‘filiform flowering scape’ (Wight Icones no. 1642, top bottom figure) is again more referable to D. microchilos Dalzell , but applying D. filiforme to either D. microchilos , or E. nana will cause several nomenclatural changes. Hence to avoid future uncertainty, the popular use of D. dalzellii over D. filiforme ( nom. confus.) is accepted here and following an updated circumscription of Porpax by Ng et al. (2018), the new combination Porpax dalzellii is proposed.

In our search for original material of Dendrobium dalzellii , the authors failed to locate Dalzell’s collection referred to in the protologue ‘from Ram Ghât’ as well as other material that Dalzell had utilized prior to describing the species; consequently, it was necessary to look for a suitable neotype. We could locate several Dalzell, Stocks & Law specimens of D. dalzellii , perhaps examined by Dalzell, Hooker, and Lindley and housed at K, CAL, and GOET. The sheets at K (K000260025, K000883997, K000883993, K000883994, K000883995) appear to be mixed collections of D. dalzellii and D. microchilos from the different localities of Bombay and Concan, thus not suitable as a neotype. The sheet at CAL (CAL0000081379) has a ticket as ‘Herb. N. Dalzell, Bombay’ and has a total of 14 plants of D. dalzellii pasted on it, but it doesn’t seem to have been Dalzell’s own collection and is excluded. Similarly, two sheets at GOET (GOET013849, GOET013850), collected by Stocks & Law from Malabar and Concan, lack Dalzell’s annotation and are not considered part of the original material. One more sheet at K (K000881643) presented by Mrs. Dalzell in 1878 has a label ‘ Eria’ in Dalzell’s handwriting, which perhaps appears to have been labelled after Lindley’s publication in 1858. This specimen comprising 22–23 plants mounted on a single sheet, is selected as the neotype.

4. Dendrobium microchilos Dalzell View in CoL , Hooker’s J. Bot. Kew Gard. Misc. 3: 345. 1851. Neotype (designated here): INDIA , Bombay, s.d., Dalzell 167 (K [K000883993!]).