Sabdariffa divaricata (Graham) McLay & R.L.Barrett, 2025

Barrett, Russell L., Yoshikawa, Vania Nobuko, McLay, Todd G. B., Duarte, Marília Cristina, Mwachala, Geoffrey & Hanes, Margaret M., 2025, Reinstatement of Sabdariffa and new combinations to support a monophyletic concept of Hibiscus (Malvaceae: Hibisceae), Australian Systematic Botany 38 (3), pp. 1-97 : 40-42

Sabdariffa divaricata (Graham) McLay & R.L.Barrett , comb. nov.

( Fig. 14 a, b .)

Hibiscus divaricatus Graham, Edinb. N. Phil. J. 9: 367–8 (1830); Abelmoschus divaricatus (Graham) Walp., Rep. Bot. Syst . 1: 309 (1842).

Type citation: ‘…was raised in spring 1829 at the Royal Botanic Garden, from seeds received from New Holland by Mr Goodsir…’. Type: Australia: Queensland: Shoalwater Bay, R. Brown [ Iter Austral. No. 5124] (neo, designated by F.D.Wilson, Austral . J. Bot . 22: 170 (1974): BM 013824568).

Hibiscus magnificus F.Muell., Fragm. 2(15): 118–119 (1861). Type citation: ‘ In montibus Newcastle Range; ad fluvia Mackenzie et Dawson. ’ Type: Australia: Queensland: Dawson River , [1857], F. Mueller s.n. (syn: MEL 18706 !); Queensland: Burdekin , 1857, F . Mueller s.n. ( K 000659813 (ex MEL)); Newcastle Range , [1857], F . Mueller s.n. ( MEL 18707 !) .

Hibiscus heterophyllus var. flaviflorus F.Muell., Fragm. 6: 170 (1868) (as ‘ flaviflorae ’). Type citation: ‘haec ad flumen Fitzroy-River nascitur.’ Type: Australia: New South Wales: Marrlaay [Macleay] River, s. dat., H. Beckler s.n. (lecto, here designated: MEL 18721 !) . Residual syn: Queensland: Herbert River, 16 May 1864, leg. ign. s.n.; ( MEL 222502 !); Port Denison , s. dat., E. F. A . Fitzlan s.n. (syn: MEL 18725 !) .

Hibiscus fitzgeraldii F.Muell., Fragm. 8: 242 (1874). Type citation: ‘Ad flumen Bowenii. Species eximie decora, a cl. R. Fitzgerald culta.’ Type: Australia: Queensland: Bowen River, [c. Dec. 1872], R.D. Fitzgerald s.n. (syn: MEL 18670!, MEL 18671!, MEL 18672! (fragm.)).

Hibiscus divaricatus var. luteus Hochr., Annuaire Cons. Jard. Bot. Genève 4: 99 (1900); Hibiscus heterophyllus subsp. luteus (Hochr.) F.D.Wilson, Austral. J. Bot. 22(1): 170, fig. 14 (1974). Type: Australia: Queensland: Rockhampton , 1877, P.A. O’Shanesy s.n. (ex herb. F. Mueller ) (syn: G 00353254 , G 00353255 ) .

Hibiscus radiatus var. luteus F.Muell. ex Hochr., Annuaire Cons. Jard. Bot. Genève 4: 99 (1900), nom. inval., pro syn.

Hibiscus divaricatus var. genuinus Hochr., Ann. Cons. Jard. Bot. Genève 4: 121 (1900), nom. inval.

Descriptions and illustrations

Graham (1830 a, pp. 367–368); Mueller (1861, pp. 118–119); Bentham (1863, p. 212); Mueller (1868, p. 170, 1874, p. 242); Bailey (1899, p. 126); Wilson (1974, pp. 170–171, fig. 15); Cooper and Cooper (2004, p. 277, fig.); Wilson (2022); Wannan (2024, 7 C, D).

Typification

The neotype of Hibiscus divaricatus selected by Wilson (1974, p. 170) is in serious conflict with the protologue that clearly refers to a different species, H. diversifolius , therefore we here reject this designation as inappropriate. We refrain from designating a new neotype pending further study and investigation as to whether original material may be extant. This species has also become popular in local horticulture in eastern Australia, therefore proposing a conserved type that maintains the current usage of the name may be advisable, despite the historical nomenclatural confusion dating back at least to Bentham (1863).

For Hibiscus magnificus F.Muell. , we refrain from designating a lectotype pending further study. Mueller described flowers but none are present on the two sheets remaining at MEL. A sheet at K from Burdekin is highly likely to be original material and the source of the floral descriptions but that location is not cited in the protologue. Additional syntypes may possibly be present at K that may be more appropriate choices as a lectotype .

There is no material at MEL annotated with the name Hibiscus heterophyllus var. flaviflorus , however there are four sheets annotated by Mueller as varieties, one as ‘var. hypoglauca’ (MEL 2222514) and three as ‘var. lutea’. We conclude that Mueller (1868, p. 170) changed the epithet from ‘lutea’ to ‘flaviforae’, given that the meaning is essentially the same and recognise the three relevant sheets as syntypes of Hibiscus heterophyllus var. flaviflorus . We here choose the only specimen with flowers present as lectotype of this name. We also note that Hochreutiner (1900, p. 99) later validated Mueller’s original variety name Hibiscus divaricatus var. luteus but the two names are treated entirely independently, in part because the identification ‘ Hibiscus radiatus var. luteus ’ is only annotated on a specimen collected after the publication of Mueller’s epithet ‘flaviflorae’.

There is another collection of Hibiscus divaricatus var. luteus at MEL (Rockhampton, 2 Jan. 1876, P. A.O’Shanesy 1580, MEL 0046761 !) that was considered as a possible syntype but the date on the label differs and the collections are not morphologically congruent, therefore we do not consider the MEL sheet to be original material and no duplicate material appears to have been retained at MEL.

Notes

A number of synonyms listed above were previously considered to be yellow-flowered forms of S. heterophylla but we prefer to place these under S. divaricata pending further study of this species complex.

Distribution

Queensland and New South Wales, Australia .

Figures

Fig. 14. (a, b) Sabdariffa divaricata. Photographs by: Russell Barrett, Sydney. (c, d) Sabdariffa diversifolia subsp. diversifolia. Photographs by Thomas Mesaglio, iNaturalist: 176035563, CC BY. (e, f) Sabdariffa diversifolia subsp. agioxillos. Photographs by Fabrício Mil Homens Riella, iNaturalist: 200507731, CC BY.