Origin and relationships of

the austral genus Abrotanella Abrotanella caespitosa 0.5 Fig. 2. Representative species of Abrotanella Fig. 4. Strict consensus of 1872 Abrotanella caespitosa 0.16 (Asteraceae). A, Cushion field in Cradle trees, 1625 steps long, from a 100 Abrotanella inconspicua Mountain National Park (Tasmania) parsimony analysis of combined Abrotanella nivigena 1.62 Abrotanella patearoa 0.58 (Asteraceae) inferred from dominated by A. forsteroides and (B) close- data. The relationships of Abrotanella patearoa 0.15 up of two capitula. C, D, Cushion of A. Blennospermatinae sensu 91 Abrotanella rosulata emarginata (dark green) and Bolax stricto and Abrotanella Abrotanella spathulata Abrotanella rostrata (Apiaceae) together with a close-up of (Asteraceae) are highlighted. Abrotanella scapigera DNA sequences ¹ 64 Steven J. Wagstaff , Ilse Breitwieser¹ & Ulf Swenson² six flowering capitula (Tierra del Fuego). Bootstrap frequencies are given Abrotanella pusilla E, F, Cushion of A. muscosa and close-up above the branches. 99 Abrotanella fertilis ¹ Allan Herbarium, Landcare Research D Abrotanella nivigena 1.27 of seven flowering capitula (Stewart Island). Abrotanella linearis PO Box 69, Lincoln 8152, New Zealand G, A. scapigera (Tasmania). H, A. fertilis 70 Abrotanella purpurea

92 Blennospermatinae [email protected] (New Zealand). All photos by Ulf Swenson. Abrotanella trichoachaenia [email protected] Abrotanella trilobata Abrotanella linearifolia 58 ² Department of Phanerogamic Botany 100 Abrotanella submarginata 97 Swedish Museum of Natural History B Abrotanella emarginata C Abrotanella muscosa PO Box 50007, SE-104 05 Stockholm, Sweden Abrotanella forsteroides [email protected] 76 Brachyglottis greyi 68 Haastia pulvinaris 100 Bedfordia salicina Dolichoglottis scorzoneroides 52 Background Traversia baccharoides 94 Senecio jacobaea 100 Senecio vulgaris Early botanical explorers to the isolated flora. I suspect that before species, which are restricted to 68 A 100 Blennosperma nanum 99 Ischnea korythoglossa southern hemisphere returned with this flora was exterminated by the Australia, New Guinea, New Zealand 61 Crocidium multicaule Petasites fragrans plants that closely resembled one glacial epoch, a few forms were widely (including Auckland, Campbell and 66 Argyrotegium fordianum another but were collected from lands dispersed to various points of the Stewart islands) and southern South Inula orientalis Cotula coronopifolia widely separated by the southern southern hemisphere by occasional America (including the Falkland Pachystegia insignis oceans. These posed a conundrum means of transport and by the aid, as Islands) (Swenson, 1995; Swenson & Calendula officinalis Dasyphyllum dicanthoides for Darwin who postulated descent halting places, of existing and now Bremer, 1997a; Heads, 1999) (Fig. 1). from a common ancestor rather than sunken islands and perhaps at the They are usually small plants (Fig. Abrotanella inconspicua New Zealand Fig. 5. Maximum likelihood tree Abrotanella nivigena 1.62 Australia multiple centres of creation. In (1859) commencement of the glacial period, 2A–H), sometimes not reaching more (-Ln = 9532.58767). Extant Abrotanella patearoa 0.58 New Zealand he wrote “I am inclined to look in by icebergs. By these means, as I than a few millimetres above the distributions of Abrotanella Abrotanella caespitosa 0.5 New Zealand Abrotanella caespitosa 0.16 New Zealand the southern, as in the northern believe, the southern shores of ground (Fig. 2E), although some form (Asteraceae) are highlighted Abrotanella patearoa 0.15 New Zealand hemisphere, to a former and warmer America, Australia, New Zealand have cushions reaching up to a metre in in colour. A scale showing the Abrotanella rosulata Subantarctic Islands number of substitutions per Abrotanella spathulata Subantarctic Islands period, before the commencement become slightly tinted by the same diameter (Fig. 2C). Often they form Abrotanella rostrata New Zealand site is provided at the bottom. Abrotanella scapigera Tasmania of the glacial period, when the peculiar forms of vegetable life.” almost continuous communities with The accessions of Abrotanella Abrotanella pusilla New Zealand New Zealand Antarctic lands, now covered with a few associated species representing nivigena from the high Abrotanella fertilis Abrotanella nivigena 1.27 New Guinea ice, supported a highly peculiar and The genus Abrotanella includes 20 other plant families (Fig. 2A). The mountains of Australia and Abrotanella linearis New Zealand New Guinea do not share a Abrotanella muscosa Stewart Island leaves are entire and somewhat Abrotanella submarginata South America common ancestor. We coriaceous (Fig. 2B, D, F) with petioles Abrotanella emarginata South America therefore propose to resurrect Abrotanella linearifolia South America that are often purple, sheathing and A. papuana S. Moore and A. Abrotanella purpurea South America Abrotanella trichoachaenia South America widening at the base. In general, they nivigena (F.Muell.) Benth. Abrotanella trilobata South America have sessile capitula and the capitula Abrotanella forsteroides Tasmania Blennosperma nanum are disciform and heterogamous with Ischnea korythoglossa Crocidium multicaule slightly dimorphic florets (Fig. 2B, D, Petasites fragrans F–H). Central florets are of two types, Senecio jacobaea Senecio vulgaris perfect or functionally male. The Bedfordia salicina Traversia baccharoides corolla is generally 4-lobed Brachyglottis greyi (occasionally 2-, 3-, or 5-lobed) and Haastia pulvinaris Dolichoglottis scorzoneroides white, purple, pale green, or yellowish. Inula orientalis Argyrotegium fordianum All cypselae lack a true pappus, but Pachystegia insignis some species have a crowned apex Cotula coronopifolia Calendula officinalis or small horns. Abrotanella along with Dasyphyllum dicanthoides

Blennosperma, Crocidium, and Ischnea 0.01 substitutions/site have been classified in subtribe Abrotanella inconspicua Blennospermatinae, a group Fig. 6. A chronogram showing Abrotanella patearoa 0.58 inferred divergence times Abrotanella nivigena 1.62 characterized by radiate, Abrotanella caespitosa 0.5 heterogamous capitula, often with transformed from the Abrotanella caespitosa 0.16 maximum likelihood tree in Abrotanella patearoa 0.15 Fig. 1. Distribution of Abrotanella (Asteraceae) showing a southern polar view of the Pacific Ocean. male central florets. Abrotanella rosulata Fig. 5. The divergence estimates Abrotanella spathulata Abrotanella rostrata were calculated using a date Abrotanella scapigera of 38 million years for the split Abrotanella pusilla Abrotanella fertilis Research Aims between Dasyphyllum Abrotanella nivigena 1.27 Abrotanella linearis (Barnadesioideae) and all other Abrotanella muscosa Asteraceae. A time scale is Abrotanella submarginata Our research aims were to test Abrotanella, whether the genus is the taxonomic implications of these Abrotanella emarginata provided at the bottom. Abrotanella linearifolia whether the Blennospermatinae are monophyletic and if monophyletic findings. Finally we wanted to estimate Abrotanella purpurea Abrotanella trichoachaenia monophyletic and to assess the subgroups could be identified. We the timing of speciation events and Abrotanella trilobata Abrotanella forsteroides phylogenetic relationships of also wanted to determine whether patterns of diversification in Abrotanella Blennosperma nanum Ischnea korythoglossa Abrotanella using ITS and 5' trnK/matK our results are congruent with and its relatives. Crocidium multicaule Petasites fragrans intron sequences. We wanted to independent molecular and Senecio jacobaea Senecio vulgaris determine the nearest relatives of morphological datasets and to assess Bedfordia salicina Traversia baccharoides Brachyglottis greyi Haastia pulvinaris Dolichoglottis scorzoneroides Inula orientalis Findings Argyrotegium fordianum Pachystegia insignis Cotula coronopifolia Calendula officinalis Abrotanella is an intriguing genus that fossil evidence from the different areas forming plants found in southern Dasyphyllum dicanthoides 37 25 7.5 1.8 is restricted to the southern of endemism. The present disjunct South America, New Zealand and Oligocene Miocene Pliocene Pleistocene hemisphere. It is only distantly related distribution of Abrotanella in South Tasmania. The crown age for to Blennosperma, Crocidium and Ischnea, America, New Zealand and Australia Abrotanella dates back 4.2 million years Fig. 3. Comparison of strict consensus trees from independent parsimony analyses of ITS nuclear ribosomal DNA (left) and chloroplast the genera with which it was placed make reconstruction of the origin (Fig. 6), which suggests that the main trnK/matK DNA (right). Bootstrap frequencies are given above the branches. in the Blennospermatinae (Figs. 3 & equivocal (Figs. 5 & 6). Apart from A. radiation accompanied mountain 4). Our results suggest that Abrotanella forsteroides, the two subclades building and episodes of glaciation ITS trnK/matK was among a group of well-defined diverged approximately 3.1 mybp, during the Pliocene and Pleistocene. 56 Abrotanella caespitosa 0.5 Abrotanella caespitosa 0.16 Abrotanella caespitosa 0.16 Abrotanella inconspicua 63 Asteraceae lineages that radiated where one (except A. muscosa) is Abrotanella fosteroides is restricted to 68 Abrotanella inconspicua Abrotanella nivigena 1.62 during the mid- to late-Tertiary. The confined to South America and the Tasmania and is sister to the remaining 97 Abrotanella patearoa 0.58 Abrotanella patearoa 0.58 Abrotanella patearoa 0.15 Abrotanella rosulata 86 chronogram suggests that the stem other to Australasia. This timing species of Abrotanella. Two main Abrotanella nivigena 1.62 Abrotanella spathulata 86 70 Abrotanella rosulata Abrotanella caespitosa 0.5 age for Abrotanella is 19.4 million years coincides with recent fossil discoveries lineages of Abrotanella were resolved, 54 Abrotanella spathulata Abrotanella patearoa 0.15 98 Abrotanella rostrata Abrotanella pusilla old (Fig. 6). We propose that from the Meyer Desert Formation one that radiated in South America Abrotanella scapigera Abrotanella rostrata 55 Abrotanella fertilis Abrotanella fertilis Abrotanella was widely distributed in (Transantarctic Mountains) at latitude and the other in Australasia. Since Abrotanella linearis Abrotanella linearis Abrotanella nivigena 1.27 Abrotanella nivigena 1.27 77 Antarctica during the mid-Tertiary 85°07' S, where tundra-like vegetation this split occurred about 3.1 million Abrotanella pusilla Abrotanella scapigera 64 Abrotanella emarginata Abrotanella linearifolia 94 and became extinct there during the was present as late as 3 mybp. This years ago, the disjunct distributions Abrotanella linearifolia Abrotanella purpurea Abrotanella muscosa Abrotanella emarginata 52 56 last glaciation, but their descendants vegetation had members of the of Abrotanella must reflect long- 100 Abrotanella submarginata Abrotanella submarginata 100 persisted in lands to the north where angiosperm families Cyperaceae, distance dispersal. Abrotanella muscosa 91 99 Abrotanella purpurea Abrotanella trichoachaenia 57 Abotanella trichoachaenia Abrotanella trilobata 61 they have since radiated. If this is a Nothofagaceae, Poaceae and is nested within a South American Abrotanella trilobata Abrotanella muscosa Abrotanella forsteroides Abrotanella forsteroides correct interpretation, Antarctica may Ranunculaceae. Perhaps the most clade, thus suggesting recent long- 58 95 Brachyglottis greyi Cotula coronopifolia Haastia pulvinaris Argyrotegium fordianum in fact have been the ancestral area interesting fossil is a cushion plant distance dispersal between South 100 Bedfordia salicina Inula orientalis Dolichoglottis scorzoneroides Pachystegia insignis Traversia baccharoides Brachyglottis greyi for Abrotanella. However, this not determined to plant family, but America and Stewart Island (New 100 90 100 Blennosperma nanum Traversia baccharoides 50 100 hypothesis is hard to test without similar in habit to extant cushion- Zealand). Ishnea korythoglossa Bedfordia salicina 61 Crocidium multicaule Dolichoglottis scorzoneroides Petasites fragrans Senecio jacobaea 67 Senecio jacobaea Senecio vulgaris Senecio vulgaris Blennosperma nanum 99 Argyrotegium fordianum Crocidium multicaule Acknowledgements Haastia pulvinaris Inula orientalis 52 Cotula coronopifolia Ischnea korythoglossa Pachystegia insignis Petasites fragrans Calendula officinalis Calendula officinalis This study was supported by the New Zealand Foundation for Research, Science and Technology and a grant from Dasyphyllum dicanthoides Dasyphyllum dicanthoides the Swedish Natural Science Research Council to US.