Pachycladon exile
| Pachycladon exile | |
|---|---|
| |
| Herbarium specimen of Pachycladon exile | |
Scientific classification 
| |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Clade: | Rosids |
| Order: | Brassicales |
| Family: | Brassicaceae |
| Genus: | Pachycladon |
| Species: | P. exile
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| Binomial name | |
| Pachycladon exile (Heenan) Heenan & A.D.Mitch.
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| Synonyms | |
|
Ischnocarpus exilis Heenan | |
Pachycladon exile is a species of plant in family Brassicaceae that is endemic to the South Island of New Zealand. Commonly known as limestone cress, it is a perennial herb with hairy leaves that is only found on one specific limestone outcrop site. It has been used to analyse principles behind adaptive radiation, together with other species of Pachycladon. Its conservation status is Threatened - Nationally Critical.
Taxonomy
[edit]Pachycladon exile is a species of plant that is endemic to the South Island of New Zealand in the family Brassicaceae.[1][2] P. exile was originally described in 1999 as Ischnocarpus exilis by Peter Heenan.[3] It was later transferred to the genus Pachycladon in 2002.[4]
P. exile is morphologically similar to P. novae-zelandiae. It can be distinguished from that species by its slender growth habit, terete ovary, slender siliques, smaller flowers, leaves and inflorescences, and a style that is small but distinct.[3] It is also similar to P. cheesemanii, as both species are polycarpic and have woody caudices, short branches, slender inflorescences, terete siliques, heterophyllous leaves, and seeds that are uniseriate and without wings.[5][6]
Description
[edit]P. exile is a perennial, polycarpic, heterophyllous rosette plant that has slender inflorescences, a woody caudex, short branches, and hairy, heterophyllous leaves.[1][3][6] Its fruit is a terete silique, and its seeds do not have wings, and are uniseriate.[6][3]
Distribution and habitat
[edit]Pachycladon exile is only found on a specific limestone outcrop site in the Waitaki Valley.[7] It is found in habitats that have a high fertility rock substrate, such as limestone, schist, and volcanics, from 10 to 1600 m above sea level.[8]
Phylogeny
[edit]P. exile is closely related to P. cheesemanii.[6][9] Alongside other Pachycladon species it has been used to analyse principles behind adaptive radiation.[10]
Conservation status
[edit]Pachycladon exile is listed as Threatened - Nationally Critical, with the qualifiers CD (Conservation Dependent), DPT (Data Poor Trend), EF (Extreme Fluctuations), OL (One Location) in the most recent assessment (2023) of the New Zealand Threatened Classification for plants.[11]
It is the sixth most endangered species in New Zealand.[7]
It was featured as Critter of the Week on 12 May 2019 on Radio New Zealand.[7]
References
[edit]- ^ a b Sooda, A; Song, J; Jameson, P E; Clemens, J (June 2011). "Phase change and flowering in Pachycladon exile and isolation of LEAFY and TERMINAL FLOWER1 homologues". New Zealand Journal of Botany. 49 (2): 281–293. Bibcode:2011NZJB...49..281S. doi:10.1080/0028825X.2010.548070. ISSN 0028-825X.
- ^ "Pachycladon exile". New Zealand Plant Conservation Network. Retrieved 2024-10-19.
- ^ a b c d B. P. J. Molloy; E. Edgar; P. B. Heenan; P. J. De Lange (March 1999). "New species of Poa (Gramineae) and Ischnocarpus (Brassicaceae) from limestone, North Otago, South Island, New Zealand". New Zealand Journal of Botany. 37 (1): 41–50. doi:10.1080/0028825X.1999.9512610. ISSN 0028-825X. Wikidata Q55756374.
- ^ P. B. Heenan; A. D. Mitchell; M. Koch (December 2002). "Molecular systematics of the New Zealand Pachycladon (Brassicaceae) complex: Generic circumscription and relationships to Arabidopsissen s. lat. and Arabis sens. lat". New Zealand Journal of Botany. 40 (4): 543–562. doi:10.1080/0028825X.2002.9512815. ISSN 0028-825X. Wikidata Q55756386.
- ^ P. B. Heenan (June 2009). "A new species of Pachycladon (Brassicaceae) from limestone in eastern Marlborough, New Zealand". New Zealand Journal of Botany. 47 (2): 155–161. doi:10.1080/00288250909509803. ISSN 0028-825X. Wikidata Q54618395.
- ^ a b c d Krithika Yogeeswaran; Claudia Voelckel; Simon Joly; Peter B. Heenan (24 September 2010). "Pachycladon". Wild Crop Relatives. Genomic and Breeding Resources. Legume Crops and Forages. Edited by C. Kole. Heidelberg, Dordracht, London, New York: Springer (2011), pp. 321, £135.00. ISBN 978-3-642-14386-1. 48 (1): 227–249. doi:10.1007/978-3-642-14871-2_14. Wikidata Q130559612.
- ^ a b c "Critter of the Week Limestone Cress". RNZ. 2019-05-10. Retrieved 2024-07-30.
- ^ Terezie Mandáková; Peter B Heenan; Martin A Lysak (29 November 2010). "Island species radiation and karyotypic stasis in Pachycladon allopolyploids". BMC Ecology and Evolution. 10: 367. doi:10.1186/1471-2148-10-367. ISSN 1471-2148. PMC 3014931. PMID 21114825. Wikidata Q33757850.
{{cite journal}}: CS1 maint: unflagged free DOI (link) - ^ K. McBreen; P. B. Heenan (January 2006). "Phylogenetic relationships of Pachycladon (Brassicaceae) species based on three nuclear and two chloroplast DNA markers". New Zealand Journal of Botany. 44 (4): 377–386. doi:10.1080/0028825X.2006.9513029. ISSN 0028-825X. Wikidata Q130559726.
- ^ Joly, Simon; Heenan, Peter B.; Lockhart, Peter J. (2014). "Species Radiation by Niche Shifts in New Zealand's Rockcresses (Pachycladon, Brassicaceae)". Systematic Biology. 63 (2): 192–202. doi:10.1093/sysbio/syt104. PMID 24335427.
- ^ Peter J. de Lange; Jane Gosden; Shannel P. Courtney; et al. (October 2024). "Conservation status of vascular plants in Aotearoa New Zealand, 2023" (PDF). New Zealand Threat Classification Series. 43: 1–105. ISSN 2324-1713. Wikidata Q130392985.