A BIZARRE PAPPUS FORM IN <i>SENECIO</i>

Drury, D. G.; Watson, Linda E.

doi:10.2307/1216115

Cited by 8 publications

(7 citation statements)

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“…pus morphology provides some insight into how S. flavus, and possibly S. mohavensis, came to be widely disjunct. In most of the species examined, variation was limited and in agreement with previous findings (Drury and Watson, 1966). Typically, almost all pappus hairs are covered with forward-pointing spines and the pappus is largely shed at achenial maturity.…”

Section: Pappus Morphology and Bird Dispersal-variation In Pap-supporting

confidence: 90%

“…Such hairs are flexuous, firmly attached, and largely unornamented. These hairs have been called ''fluked hairs'' (Drury and Watson, 1966) the frequent presence of backward-pointing projections at the swollen tip. Senecio flavus departed from this general pattern by having ϳ100 fluked hairs per achene, accounting for onethird of the pappus.…”

Section: Pappus Morphology and Bird Dispersal-variation In Pap-mentioning

confidence: 99%

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Repeat intercontinental dispersal and Pleistocene speciation in disjunct Mediterranean and desert Senecio (Asteraceae)

Coleman

Liston

Kadereit

et al. 2003

American J of Botany

100

129

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To explore the biogeographic history of Mediterranean/arid plant disjunctions, Old and New World Senecio sect. Senecio were analyzed phylogenetically using nuclear ribosomal DNA sequences (ITS). A clade corresponding to sect. Senecio was strongly supported. Area optimization indicated this clade to be of southern African origin. The Mediterranean and southern African floras were not distinguishable as sources of the main New World lineage, estimated to have become established during the middle Pliocene. Another previously suspected recent dispersal to the New World from the Mediterranean was confirmed for the recently recognized disjunction in S. mohavensis. The loss of suitable land connections by the Miocene means that both New World lineages must represent long-distance dispersal, providing the first evidence of repeat intercontinental dispersal in a Mediterranean group. In contrast, migration within Africa may have utilized an East African arid corridor. Recent dispersal to northern Africa is supported for S. flavus, which formed part of a distinct southern African lineage. Novel pappus modifications in both disjunct species may have enabled dispersal by birds. An estimated early Pliocene origin of sect. Senecio coincides with the appearance of summer-dry climate. However, diversification from 1.6 BP highlights the importance of Pleistocene climate fluctuations for speciation.

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Section: Pappus Morphology and Bird Dispersal-variation In Pap-supporting

confidence: 90%

Section: Pappus Morphology and Bird Dispersal-variation In Pap-mentioning

confidence: 99%

Repeat intercontinental dispersal and Pleistocene speciation in disjunct Mediterranean and desert Senecio (Asteraceae)

Coleman

Liston

Kadereit

et al. 2003

American J of Botany

100

129

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“…Karyotype analyses showed L. nelumbifolia and C. stenoglossum were both diploid with 2n = 58 ( Liu et al 2001 ; Ren 2012 ), which makes homoploid hybridization possible ( Kou et al 2017 ). Combining the ambiguous morphological differences and phylogeny between Ligularia and Cremanthodium , the above ecological factors further provided possibilities for natural hybridization between L. nelumbifolia and C. stenoglossum , supporting the view that Cremanthodium species are alpine derivatives of Ligularia species ( Wulff 1944 ; Drury 1966 ). Although the morphology and phylogeny of Ligularia and Cremanthodium are unclear, the current study may offer a new insight into their relationship by sampling the potential hybrids during the field survey.…”

Section: Discussionmentioning

confidence: 65%

“…Both genera are non-monophyletic, clustering into the Ligularia–Cremanthodium–Parasenecio (L–C–P) complex, a fairly diversified clade that contains more than 200 species that are endemic to the QTP in eastern Asia ( Liu et al 2006 ; Ren 2012 ). Traditionally, Cremanthodium species were regarded as alpine derivatives of Ligularia species ( Wulff 1944 ; Drury 1966 ); however, they are still recognized as two genera. Given the close relationship and high diversity of Ligularia and Cremanthodium on the QTP ( Liu et al 2006 ), it can be speculated that hybridization might also play a role in their respective diversification and ambiguous phylogeny.…”

Section: Introductionmentioning

confidence: 99%

The natural hybridization between speciesLigularia nelumbifoliaandCremanthodium stenoglossum(Senecioneae, Asteraceae) suggests underdeveloped reproductive isolation and ambiguous intergeneric boundary

Yang

Wang

et al. 2021

AoB PLANTS

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Natural hybridization is frequent in plants and is considered an important factor facilitating speciation. The natural intergeneric hybridization between Ligularia and Cremanthodium was previously confirmed using a couple of DNA markers. However, the mechanism of this intergeneric hybridization and the role of reproductive isolation in the process of hybridization remain unclear. Here we used double digest restriction-site associated DNA sequencing (ddRAD-Seq) to further quantify the occurrence of hybridization, the genetic structure of the hybrid population and the role of reproductive isolation between Ligularia nelumbifolia and Cremanthodium stenoglossum. The results based on the ddRAD-seq SNP datasets indicated that hybridization between L. nelumbifolia and C. stenoglossum was restricted to F1s, and no gene introgression was identified between these two species. STRUCTURE analysis and ML tree results showed a slightly larger genetic contribution of L. nelumbifolia to putative hybrid F1s. We deduced that the reproductive isolation between these two parent species is not well developed but still strong enough to maintain the genetic integrity of the species, and that their F1s are sterile or with low fertility. Given the poorly resolved phylogenetic relationship between Ligularia and Cremanthodium, the occurrence of natural hybridization between L. nelumbifolia and C. stenoglossum may provide new insights into the re-circumscription and re-delimitation of these two genera.

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“…in a revision of the genus, showed that the Australasian species are distinct from the New World representatives and transferred the former to Senecio. Recent studies in comparative morphology (Drury and Watson, 1966) and cytology (Afzelius, 1967, andOrnduff et al, 1967) in Senecioneae, a tribe of Compositae to which both Senecio and Erechtites belong, tend to support Belcher's action. However, since Allan's nomenclature is still favoured in New Zealand by popular usage we have retained it in the present study to avoid confusion.…”

Section: Introductionmentioning

confidence: 98%

A numerical study of the variation in the New Zealand erechtites arguta-scaberula complex (Senecioneae-Compositae)

Drury¹,

Randal

1969

New Zealand Journal of Botany

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Thirteen numerical attributes taken from phyllarics. calycule. peduncle and florets were recorded for a sample of 6S spt.'Cimens representing the New Zealand Er«hlius UTgllla (syn. Stn~do glomtralus)-E.r~cllfius scab~r/lla (syn. S~,,~ci() "ispidllills) complex. The comparative data were subjected to computer analyses using Squared Euclidean Distance (/)/) and Gower's Index as similarity statistics in conjunction with Nearest. Median and Furthest neighbour and Centroid (C) sorting strategies during the commissioning of ASSORT. a package of interrelated Algol prccedures. The resulting agglomerative polythetic classifications conform to a basic structure eumplified by the D' -C result. Two major groups consisting of four and five subgroups respectively were detected from the computed hier· archy. Thirteen additional characters taken from stem. leaf. involucre. corolla and achenes together with geographical data were used to show that the two major groups and only one subgroup exhibit taxonomic properties. Reference to nomen· c1atural type material and other critical specimens for the complex confirm the presence in New Zealand of S~n~ci(J giom~raws and S. "Ispldlllllf varieties IIIspl. duius and scab"ui,lS. Our results do not sustain the sUfgestion that S. Mspldlli".f and S. giom~ral/ls hybridise freely over much of their argely overlapping range. lIowever. the analyses expose an assemblage intermediate in floral details betweel' .\. hlspiduius variety scub""i'!s and variety hispidui"s for which an hybrid origin IS postulated. S. glc~m~rulus In ~ew Zealand shows partial segregation into two elemenU. In numerical taxonomIC: terms the study demonstrates the value of the ASSORT package as applied to a standard taxonomic problem. Furthermore. the constituent procedures would sc~m to rrovide a realistic framework in which to carry out the much needed experlmenta research into taxonomic theory.N.z. JI B,,'. 7: S6-7S

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A BIZARRE PAPPUS FORM IN SENECIO

Cited by 8 publications

References 0 publications

Repeat intercontinental dispersal and Pleistocene speciation in disjunct Mediterranean and desert Senecio (Asteraceae)

Repeat intercontinental dispersal and Pleistocene speciation in disjunct Mediterranean and desert Senecio (Asteraceae)

The natural hybridization between speciesLigularia nelumbifoliaandCremanthodium stenoglossum(Senecioneae, Asteraceae) suggests underdeveloped reproductive isolation and ambiguous intergeneric boundary

A numerical study of the variation in the New Zealand erechtites arguta-scaberula complex (Senecioneae-Compositae)

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