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Post by Melanie on Jan 27, 2007 12:49:21 GMT 1
Common name: Bastard Gumwood
Justification C. rotundifolium was thought to have been extinct by the end of the 19th Century with the last known trees growing at Longwood, Black Field and Horse Pasture. However, Stedson Stroud rediscovered this species in 1982 as one tree growing out from a cliff at the southern edge of Horse Pasture. This tree was destroyed by a gale in 1986 and the species is now extinct in the wild.
Range C. rotundifolium is extinct in the wild.
Habitat and Ecology A tree, formerly common on dry areas, 400 – 520 m. According to Cronk (1989) the Bastard Gumwood was associated with the dry gumwood woodland 300-500 m. and to some extent wet gumwood woodland 500-650 m.
Threats Historically used a fuel wood. Regeneration prevented by browsing livestock.
All trees currently growing at Pounceys are smothered in lichen growth. Lichens are parasitic and will be an additional burden on already weakened trees but they also harbour moth larvae which are known to burrow into living wood (of Redwoods, Gumwood and She Cabbage, RCW pers. obs) further compounding senescence. White Ants Cryptotermes are pests present at both Pounceys and Scotland sites.
Conservation Measures Trees have been successfully established in cultivation at Pounceys and the ECS Nursery at Scotland and form the basis of recovery efforts for the species. Seedlings raised in 2002 from seed from tree 8 at Pounceys have now been planted at Barren Ground. However because of barriers to reproduction this species still faces an uncertain future in cultivation unless consistent effort is made to propagate it through seed.
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Post by Melanie on Feb 11, 2007 20:38:59 GMT 1
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Post by Melanie on Feb 11, 2007 20:40:51 GMT 1
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Post by Surroundx on Apr 24, 2011 6:52:36 GMT 1
Bastard gumwood Commidendrum rotundifolium (Compositae) (EW): formerly one of the common gumwoods occurring in dry areas, by the end of the 18th century stands were reduced to a few isolated localities and the species was considered extinct at the end of the 19th century. A tree was rediscovered on an inaccessible cliff at the southern edge of Horse Pasture in 1982 but, by 1986, it had blown down in a gale. Nineteen trees, seedlings of the tree which blew down, were planted at Pounceys in the mid-1980s. Attempts to root cuttings have failed and seed from these trees have so far failed to germinate. Source: jncc.defra.gov.uk/pdf/OT_StHelena.pdf |
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Post by alex on Apr 26, 2011 18:19:37 GMT 1
The future perspectives for this species seem to be quite sad.
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Post by Peter on Apr 28, 2011 9:04:08 GMT 1
I'm a bit confused about this species....(see my questions in red)... Currently I'm working on a new part for my website about captive breeding successes and failures. This part will be based on "Last Stand in Captivity: A preliminary analysis of all species that were ever "extinct in the wild", an unpublished excel-document prepared by K.C. Zippel for IUCN/SSC Conservation Breeding Specialist Group as a template for a proposed online database. That document includes this species. With the support of K.C. Zippel I'm now trying to build such an online database. Online I've found some information, but not much: "Trees of the species had been successfully established in cultivation at Pounceys in Saint Helena and the ECS Nursery at Scotland and formed the basis of recovery efforts for the species (Cairns-Wicks 2003). Seedlings raised in 2002 from seed from tree 8 at Pounceys had been planted at Barren Ground (Cairns-Wicks 2003)." Can the planted ones at Barren Ground be seen as a reintroduction?"Apparently, the last of this species to survive in cultivation were damaged by gales in 2008 and the survival of the species was in doubt. In December 2009, Lourens Malan, a horticulturist working for the island's conservation department under the Critical Species Recovery Project, discovered a wild tree growing on a cliff. A local team of botanists, conservationists and volunteers commenced an intensive programme of hand pollination and seed collection of the remaining cultivated tree, while protecting it from insects that may cross-pollinate with nearby false gumwoods. (Wikipedia contributors 2010)." Was the 2009 rediscovery a wild specimen or a cultivated one?"The last tree of this species is found on the tiny South Atlantic island of St Helena, and it is dying. The tree ( Commidendrum rotundifolium) is enclosed in netting to prevent insects cross-pollinating with its near neighbour, the False Gumwood. But even then because there are no other individuals in existence, the tree must self-pollinate, which it stubbornly resists. And so it needs some help Every day, botanist Phil Lambdon visits the site along with local conservationists. The team delicately uses small paint brushes to collect pollen grains, which they spread from one flower to another. But the odds are still against the Bastard Gumwood. "The tree just doesn't want to pollinate itself," said Dr Lambdon, the botanist visiting from Kew Gardens who is in charge of the effort. "Only around 1 in 10,000 pollen grains have the small genetic mutation which will allow self-pollination to take place. "It's like a needle in a haystack. The work is painstaking and very slow." (Hancock 2010)" Is there now truly only one surviving specimen of Commidendrum rotundifolium?References used: |
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Post by alex on Apr 28, 2011 10:11:53 GMT 1
Is there now truly only one surviving specimen of Commidendrum rotundifolium? As far as I learned from the web, there is indeed only a single tree left, and it seems that all of the little trees, that were artificially planted, are dead now.  |
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Post by Surroundx on Sept 18, 2016 5:14:44 GMT 1
Hybrid plants preserve unique genetic variation in the St Helena endemic trees Commidendrum rotundifolium DC Roxb. and C. spurium (G.Forst.) DCAbstract The island of St Helena in the South Atlantic Ocean has a rich endemic flora, with 10 endemic genera and 45 recognised endemic species. However, populations of most endemic species have undergone dramatic reductions or extinction due to over-exploitation, habitat destruction and competition from invasive species. Consequently, endemic species are likely to have lost genetic variation, in some cases to extreme degrees. Here, the entire extant wild populations and all planted trees in seed orchards, of two critically endangered species in the endemic genus Commidendrum (Asteraceae), C. rotundifolium and C. spurium, were sampled to assess levels of genetic variation and inbreeding. Six new microsatellite loci were developed from next-generation sequence data, and a total of 190 samples were genotyped. Some seed orchard trees contained alleles from both wild C. rotundifolium and C. spurium indicating they could be hybrids and that some backcrossing may have occurred. Some of these trees were more similar to C. rotundifolium than C. spurium both genetically and morphologically. Importantly, allelic variation was detected in the putative hybrids that was not present in wild material. C. rotundifolium is represented by just two individuals one wild and one planted and C. spurium by seven, therefore the seed orchard trees comprise an important part of the total remaining genetic diversity in the genus Commidendrum. Source: Gray, Alan, Perry, Annika, Cavers, Stephen, Eastwood, Antonia, Biermann, Michelle, Darlow, Andrew, Thomas, Vanessa and Lambdon, Phil. (2016). Hybrid plants preserve unique genetic variation in the St Helena endemic trees Commidendrum rotundifolium DC Roxb. and C. spurium (G.Forst.) DC. Conservation Genetics. doi:10.1007/s10592-016-0884-8 [ Abstract]
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Post by koeiyabe on Jan 10, 2019 2:18:22 GMT 1
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