Salsola kali var. strobilifera, Bentham, 1870

Mosyakin, Sergei L., 2019, Salsola strobilifera (Chenopodiaceae), a new combination for a remarkable Australian taxon, Phytotaxa 409 (5), pp. 283-290 : 285-286

Lectotypification of Salsola kali var. strobilifera

To the best of my knowledge, no valid lectotypification has been published for Salsola kali var. strobilifera . Bentham (1870: 207–208) reported in the protologue the following information: “ Var. strobilifera . Flowers densely clustered in globular heads with the points of the subtending bracts protruding like the scales of a pine-cones.—Darling desert and Mount Murchison”. Consequently, the lectotype should be selected from specimens collected in the mentioned sites and studied by Bentham in the course of preparation of his account of Salsola for Flora Australiensis.

Wilson (1984: 314) cited the type of Salsola kali var. strobilifera as “ T: Darling desert and Mount Murchison ; no collectors cited; n.v. [non vidi – S. M.]” and listed the name among supposed synonyms (in fact, mainly misapplied names) of S. kali that he accepted in a very wide sense. Rilke (1999: 112) also did not typify the name but just cited the geographic information from the protologue: “ Darling desert und [sic! – S. M.] Mount Murchison ”; no type information was reported either in the list of studied specimens of her informally named entity S. tragus “strobilifera ” ( Rilke 1999: 131–132).

I was able to locate online three supposedly original specimens of Salsola kali var. strobilifera , all preserved at K. Two specimens (K000899590, and K000899591) are mounted on one sheet and bear the typographically printed curatorial labels “FLORA AUSTRALIENSIS | named by Mr. BENTHAM”, which means that these specimens were studied by Bentham for his Flora Australiensis. The handwritten original labels indicate that the specimens were collected during the Burke and Wills Victoria Exploring Expedition of 1860–1861 (see Willis 1962, Orchard 1999, Gillbank 2011, Wood & Darragh 2016, and references therein).

The specimen K000899590 (image available from http://apps.kew.org/herbcat/getImage.do?imageBarcode= K000899590 and https://plants.jstor.org/stable/10.5555/al.ap.specimen.k000899590) bears the label “ Salsola Australis R.Br. | near the Darling River. | Vict. Exp. Dr. Beckler” and is undated. It was collected in New South Wales by Hermann Beckler (1828–1914), a German-born plant collector who in 1860–1861 participated in the Victoria Exploring Expedition as a medical officer and botanist ( Willis 1962, Gillbank 2011, Wood & Darragh 2016). The handwritten identification “ S. Kali Linn. V. 207” (meaning Vol. 5, page 207 of Bentham’s Flora Australiensis) is written in black ink directly on the sheet neat the printed label. Judging from the published volume and page information provided, this identification was added after the date of publication of vol. 5 of Flora Australiensis ( Bentham 1870).

The specimen K000899591 (image available from http://apps.kew.org/herbcat/getImage.do?imageBarcode= K000899591 and https://plants.jstor.org/stable/10.5555/al.ap.specimen.k000899591; on the same sheet with K000899590) has the following label: “Decemb. 29 1860 | Salsola Australis | R.Br. | var. strobulifera [sic! – S.M.]. | from Nangawera to Yellowinchi | Vict. Expl. Exped.”. The locality is transcribed in JSTOR Global Plants (see the link above) as “from [Nangauera] to Yellowin”, but Willis (1962: 256) provided the correct site information and specified that this locality is “just N. of Mt. Koonenberry”, New South Wales.As in the previous specimen, there is the handwritten identification, “ S. Kali Linn. | var. strobilifera [probably originally written as “ strobulifera ”, but then corrected – S.M.] | V. 207” on the sheet near the printed label (see the note above, on a similar identification of K000899590). This specimen was most probably also collected by Beckler (see Willis 1962). According to Willis (1962: 259), specimens of Salsola were collected during the Victoria Exploring Expedition by three collectors: Beckler (see below), W.F. Wheeler (from “between Stokes Range and Cooper’s Creek”), and J.P. Murray (from Cooper’s Creek). Beckler collected Salsola plants at three localities (site numbers correspond to those in Willis 1960): Menindee, 15 October 1860 (Locality 13); “from Nangawera to Yellowinchi”, 29 December 1860 (Locality 19); and “near Caryapundy Swamp and Puria Cr. [Creek – S.M.], almost on the Queensland border (‘Cariapundi’ of Beckler)”, 19/ 22 March 1861 (Locality 24). The last collection site corresponds to the specimen in MEL collected by Beckler on 22 March 1861 and currently identified as S. tragus subsp. grandiflora (MEL0605419A, data available from https://avh.ala.org.au/occurrences/496ad316-ec2e- 41dc-92fa-a23fb5cadbca; Council of Heads of Australasian Herbaria 2006 –onward).

The third specimen (K000899592, image available from https://plants.jstor.org/stable/10.5555/al.ap.specimen. k000899592 and http://apps.kew.org/herbcat/getImage.do?imageBarcode=K000899592) has the label “ Salsola Kali var. strobilifera | Australia F. Mueller | Comm. [Communicated by? – S.M.] Dr. W.T. Walters | June 1895 ” written directly on an envelope, and the anonymous identification/typification label “ Typus | S. kali var. strobilifera Benth. | Fl. Austral. 5: 207 (1870) ”. As far as I know, this typification has never been published and it is not effective according to the Shenzhen Code. The specimen contains one larger (ca. 11 cm long) branch fragment with two strobile-like terminal inflorescences, and two smaller inflorescence fragments. Most probably that specimen is a fragment of a more complete specimen (probably from the MEL herbarium where most of Mueller’s specimens are deposited) collected either by Mueller or by one of his correspondents. The date “ June 1895 ” may refer to the date of provenance of the fragment rather than the collection date. However, if it is the actual collection date, the specimen cannot be regarded as part of original material because the name S. kali var. strobilifera was published by Bentham in 1870. There is no evidence that K000899592 has been seen by Bentham prior to his publication of the variety name . The collection locality is also unknown. Because of these arguments I do not consider that specimen suitable for lectotypification.

Morphologically the specimens K000899590 and K000899591 are very similar and, in my opinion, indeed belong to the same taxon. The plants are glabrous or nearly so (as it was also reported by Chinnock (2010) for his informal subsp. “ Strobilifera ”), with scattered hispid pubescence only on bracts/bracteoles in terminal inflorescences. The branching habit is rather noteworthy: lower branches and leaves are opposite or subopposite, which is uncommon in other taxa of Salsola sensu stricto. However, a similar branching pattern and leaf arrangement are seen in the type specimen of the taxon described as Salsola brachypteris from Java (see Mosyakin 2017b: 524, 2018: 9). The wings on inner perianth segments (tepals) in specimens K000899590 and K000899591 are rather large, similar in their size and shape to those in S. australis sensu stricto and much larger than corresponding wings in S. tragus (in which three wings on outer tepals are much larger than two small wings on inner tepals, see Rilke 1999, Hrusa & Gaskin 2008, etc.). However, in typical forms of S. australis (as well as in the type of S. kali subsp. austroafricana Aellen (1961: 27) , which is now synonymized with S. australis ) the tips of perianth segments above the wings are short, lax, and often almost open, exposing or barely covering the fruit (see Hrusa & Gaskin 2008). In contrast, tepal tips in S. kali var. strobilifera (sensu stricto) are larger than those in S. australis , forming a rather lax but well visible cone-shaped “beak” above the wings. In my opinion, these morphological characters may indicate that typical “ strobilifera ” plants are more closely related to S. australis sensu stricto than to other Australian or Eurasian taxa.

Having considered the above arguments, I think that the specimen K000899590is the best choice for lectotypification because it better corresponds to the locality mentioned in the protologue (“Darling”) and is more representative (better preserved) than the specimen K000899591 mounted on the same sheet.

Several of the studied specimens of “strobiliferous” Salsola from Australia differ from the proposed type of S. kali var. strobilifera (see lectotypification below) in having larger and stiffer tepal tips forming a longer and narrower cone-shaped column above the wings, and usually also denser hispid pubescence, especially in the inflorescence. Probably these plants represent another “strobilifera ”-like taxon, which, judging from its morphology, might be closer to S. sabrinae ( S. tragus subsp. grandiflora ). These morphological differences, even if based on limited material, confirm the conclusion of Borger (2007) and Borger et al. (2008) regarding the existence of at least two (probably three?) native “strobilifera ”-like taxa in Australia. Unfortunately, morphological descriptions of such plants in Borger et al. (2008) and Chinnock (2010) are rather generalized and not particularly diagnostic, not containing information about morphological characters of fruits and fruiting perianth segments, which are important in species-level taxonomy of Salsola .

The ovoid to almost globular (pine-cone-shaped, “strobiliferous”) terminal inflorescences of “strobilifera ”-like Australian plants are easily detached (broken off) at maturity, which is evident even from herbarium specimens, in which such separated “pine-cones” are often kept in envelopes (see, for example, the images of K000899590, and K000899591). Most probably this feature can be viewed as a specific dispersal adaptation and these structures are in fact the dispersal units acting as miniature “tumbleweeds”. Plants of Salsola sensu stricto may have different dispersal strategies (see a brief overview in Mosyakin 2018, and references therein). Borger (2007) and Borger et al. (2007, 2009) reported data on Australian Salsola plants that easily shed fruits at maturity and those that mainly retain the fruits on the plants (which in that case are usually easily detached from the root, forming tumbleweeds). Unfortunately, precise morphological characters of plant groups with different dispersal strategies were neither reported nor matched with predominant dispersal modes. Some differences in dispersal modes of selected taxa of Salsola were also discussed by Hrusa & Gaskin (2008). Chinnock (2010: 77) mentioned that his informal S. australis subsp. Strobilifera “is very widespread in Australia, well-defined and probably requires specific status. Unlike S. australis subsp. Compact this form does not appear to become a tumbleweed”, an important observation pointing at another main dispersal mode as compared to mainly tumbleweed-forming morphotypes.

In any case, the morphological differences of the taxon originally described as Salsola kali var. strobilifera distinguishing it from S. australis and other native Australian and/or Eurasian taxa of Salsola are not restricted only to the peculiar globular to ovoid terminal inflorescences but also include characters of fruits and tepals, contrary to what has been suggested by Wilson (1984), Rilke (1999), and some other authors. Even less pronounced morphological differences are considered by Eurasian botanists as sufficient for recognition of separate species [see, for example, treatments in Rilke (1999), Zhu et al. (2003), Hrusa & Gaskin (2008), Brullo et al. (2015a, 2015b), and recently validated taxa S. hartmannii Sukhor. (in Sukhorukov et al. 2019: 114) and S. austrotibetica Sukhor. (in Sukhorukov et al. 2019: 122)]. Thus, in my opinion, S. kali var. strobilifera should be regarded as a separate species, which is native to Australia. The relevant new combination is provided below.