(3117) Proposal to conserve the name <i>Dendrobium ×delicatum</i> against <i>D. ×speciokingianum</i> (<i>Orchidaceae</i>)

(3117) Dendrobium ×delicatum (F.M. Bailey) F.M. Bailey, Queensl. Fl. 5: 1527. Apr 1902 (D. speciosum var. delicatum F.M. Bailey in The Brisbane Courier 38(8000): 7. 1 Sep 1883) [Angiosp.: Orchid.], nom. cons. prop. Typus: [Australia,] Queensland, Main Range, Crow & Hartmann (BRI barcode BRI-AQ0023075). (=) Dendrobium speciokingianum T. Lawr. in Garden (London, 1871–1927) 49: 201. 14 Mar 1896 (‘specio-kingianum’), nom. rej. prop. Typus: non designatus. In eastern Australia there is a sporadic, naturally occurring hybrid between Dendrobium speciosum Sm. (Exot. Bot. 1: 17, t. 10. 1805) and D. kingianum Bidwill ex Lindl. (in Edwards's Bot. Reg. 30(Misc.): 11. 1844) widely known by the name D. ×delicatum (F.M. Bailey) F.M. Bailey. This hybrid was originally described as D. speciosum var. delicatum F.M. Bailey (in The Brisbane Courier 38(8000): 7. 1883), based on plants from the “Main Range, Collected by B. Crow & C.H. Hartmann”. A specimen derived from the gathering by Crow and Hartmann is now preserved in the Brisbane Herbarium (BRI barcode BRI-AQ0023075) and, as the only preserved material derived therefrom, may be the holotype though it is now in poor condition. Bailey raised the variety to species rank (Queensl. Fl. 5: 1527. 1902). A prolonged debate regarding the possible origins for D. delicatum then followed, lasting until the mid-1960s when the consensus view that the taxon was a naturally occurring hybrid emerged (see Grundon in Orchadian 11: 4–13. 1993 and Renner in Telopea 27: 141–146. 2024 for reviews). This hybrid has a contemporaneous and parallel naming history rooted in orchid horticulture on the other side of the world. The artificial cross of Dendrobium speciosum and plants thought to be D. kingianum was made and raised by Mr H.W. White in the nursery of Sir Trevor Lawrence (2nd Baronet) (1831–1913), a surgeon, Member of Parliament, and enthusiastic orchid grower. Plants from this crossing were first exhibited in 1892 (see Gard. Chron., ser. 3, 11: 409. 1892) and were subsequently granted an Award of Merit by the Royal Horticultural Society when exhibited again in early 1896. Reports of this award appeared in The Garden, Orchid Review, The Gardeners’ Chronicle, and the Journal of the Royal Horticultural Society of London shortly thereafter. Though D. kingianum was listed as a parent, the plant used was almost certainly a mislabelled D. ×delicatum, plants of which were habitually and incorrectly attributed to D. kingianum var. album B.S. Williams (in Warner & Williams, Orch. Album 7: t. 332. 1888) at that time (Adams in Telopea 29: 163–171. 2025). The report of the Award of Merit to Dendrobium speciokingianum (in Garden (London, 1871–1927) 49: 201. 1896, as ‘specio-kingianum’) fulfils the requirements for valid publication. Though derived from the two imputed parental species epithets, the epithet “specio-kingianum” does not violate ICN Art. H.10.2 (see Ex. 4; Turland & al. in Regnum Veg. 162. 2025) so the name D. speciokingianum satisfies the requirements for epithet formulation, and the description, albeit brief, describes more than purely aesthetic qualities (Art. 38.3). No original material was cited and none seems to have been preserved, though the protologue speculates that “this is one of the Queensland or New South Wales Dendrobes undoubtedly”. Although the name is not ascribed to anyone (Art. 46.3), the fact that the plant was owned and exhibited by Lawrence suggests the name should be attributed to him. In Australia, the publication of Dendrobium speciokingianum was understandably overlooked and the name D. ×delicatum became established in botanical and horticultural spheres. The name D. ×delicatum appears in flora treatments for the Australian states of Queensland and New South Wales (Stanley & Ross, Fl. Southeast. Queensland 3: 435. 1989; Weston in Harden, Fl. New South Wales 4: 231. 1993), in scientific literature (Rupp in Proc. Linn. Soc. New South Wales 56: 133–138. 1931, 58: 223–228. 1933; Clements in Austral. Orchid Res. 1: 51. 1989), in popular works on Australian orchids (Rupp, Orchids New South Wales: 114. 1943; Jones, Nat. Orchids Austral.: 446. 1988, ed. 3: 692. 2024, as Thelychiton), in works on Australian orchid cultivation and hybridization (Upton, Dendrobium Orchids Austral.: 142. 1989), and in orchid society journals (Schmidt in Austral. Orchid Rev. 1(4): 16. 1936; Rupp in Austral. Orchid Rev. 3: 37–40. 1938; Weinthal in Austral. Orchid Rev. 4: 44–50. 1939; Blombery in Orchadian 2: 10–11. 1965; Kirkland in Orchadian 2: 78–81. 1967; Gregory in Orchadian 5: 184. 1978; Grundon, l.c.). The name D. ×delicatum has also been used in books and major review papers on the parent species, D. kingianum and D. speciosum (e.g., Adams & Lawson, Dendrobium kingianum: Unique Austral. Orchid. 1995; Adams in Bot. J. Linn. Soc. 166: 105–126. 2011, Guide Dendrobium Austral. 2015, in Orchids (West Palm Beach) Suppl. 15: 1–81. 2023, l.c. 2025; Dockrill, Austral. Indigen. Orchids. 1969, ed. 2. 1992). The naming convention used in the Australian horticultural sector has been propagated with the export of cultivated plants overseas. Between 1993 and 2018, 26 horticultural awards were received by 17 cultivars of Dendrobium ×delicatum in Australia, Germany, New Zealand, and the United States, including D. ×delicatum ‘Pretty Good’ HCC/AOC(2003) ACC/AOC(2003), D. ×delicatum ‘Big Red’ HCC/OSNSW(2009), D. ×delicatum ‘Marie’ ACM/OSNSW(2011), D. ×delicatum ‘Mt. Airy’ CCE/AOS(2014), D. ×delicatum ‘György’ GM/DOG(2017) BM/DOG(2017), D. ×delicatum ‘Margaret’ CCC/OCNZ(2018) (ACC = Award of Cultural Commendation, ACM = Award of Cultural Merit, BM = Bronze Medal, CCC = Certificate of Cultural Commendation, CCE = Certificate of Cultural Excellence, GM = Gold Medal, HCC = Highly Commended Certificate; AOC = Australian Orchid Council, AOS = American Orchid Society, DOG = Deutsche Orchideen-Gesellschaft, OCNZ = Orchid Council of New Zealand, OSNSW = Orchid Society of New South Wales), among others. Though discrimination between plants of wild origin and those of horticultural origin is not always clear the number and geographic distribution of awards illustrates how widely established in horticulture the name D. ×delicatum has been. Since 2014 there has been a push to reinstate Dendrobium ×speciokingianum as the correct name for naturally occurring hybrids and artificial hybrids, given the requirements of both ICN and ICNCP (Brickell & al. in Scripta Hort. 18. 2016) were fulfilled when the award was reported by The Garden (Shaw in Orchid Rev. Suppl. 122: 36. 2014). This approach appears to be a consequence of the registration of the plant of Lawrence, which has different parentage from those studied in Australia by Bailey. Consequently some of these plants, though awarded as D. ×delicatum, are now listed as D. ×speciokingianum or D. Specio-kingianum on societal web pages, e.g., the plant awarded as Dendrobium delicatum ‘Big Red’ [sic] is now listed online as D. Specio-kingianum ‘Big Red’. However, the name D. ×delicatum remains in widespread use in horticultural circles, including in Australia and overseas, for plants of wild origin, and the name has a long-established history of use in botanical and horticultural literature in Australia. This proposal is to conserve the name Dendrobium ×delicatum against D. ×speciokingianum under Art. 14, which will allow D. ×delicatum to remain the name used for naturally occurring individuals of this familiar and horticulturally significant orchid. Conservation will avoid the replacement of an established name of known origin with a relatively unfamiliar name of obscure origin, which would be confusing and disruptive to orchid enthusiasts, horticulturalists, and taxonomists.