| Brydie.crates/sandbox | |
|---|---|
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Scientific classification 
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| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Clade: | Asterids |
| Order: | Apiales |
| Family: | Araliaceae |
| Genus: | Pseudopanax |
| Species: | P. colensoi
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| Binomial name | |
| Pseudopanax colensoi (Hook.f.) Philipson
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Description edit
Pseudopanax colensoi (Hook.f.) Philipson var. colensoi is a small multi-branched evergreen shrub or tree that typically grows between 5-8m tall but can surpass this height depending on environmental conditions[1]. This plant is dioecious, meaning it has male reproductive organs in one individual and female organs in the other.[2][1] The leaves of this plant have an alternate arrangement with leaflets ranging from 3, to 5, or up to 7 in a palmate form.[1] The leaflets on Pseudopanax colensoi are formed on short/absent petiolules, otherwise known as subsessile.[3][1] The petiolule stouts, which are the parts of the leaf that connect to the main stem, are 5-20cm in length and have sheathing branchlets at the base with a small stipule, the leaflike outgrowth seen at the leaf base or stalk.[4][1] The branchlets are spreading and fleshy whilst brittle.[1] The leaflets have a varying shape displayed as narrow-ovate to broad elliptic-oblong, that cuneately narrow to the petiolule.[5][1] The leaflets are also coriaceous, meaning they are leathery and tough but remain flexible.[6][1] The leaflets have a serrate-denate leaf margin in the upper 2/3-3/4 portion of the leaf, whilst its general shape changes from acute to obtuse as the leaf extends out, coming to an acute apex (tip of the leaf).[1] The midrib is distinct and obvious from above and below with the lateral veins obscure/concealed.[1] The leaves are a glossy, darker green providing a bold shiny aesthetic.[1] The terminal lamina/leaf blade is 5-17 x 2-11cm with the lateral leaflets decreasing in size as they grow closer to the branchlet.[7][1] The terminal leaflet is 0-5-10-(15)mm long, and gets shorter on the lateral leaflets.[1] These are light green with a reddish base.[1] Pseudopanax colensoi forms its flowers from a compound terminal umbel.[5][1] An umbel is a rounded cluster of flowers where the stalks of each flower all grow from the same main stem, alike to the ribs of an umbrella.[8] There are 8 primary rays/branchlets, 10-12 secondary rays with umbellules of 5-10 flowers in each.[1] The calyx truncate, which is the outer layer of a flower pod, is five-toothed and opens to reveal 5 cream or green flower petals that are shaped from ovate, to triangular, to acute.[9][1] These flowers are 5mm in diameter.[1] There are 2 locules, with each holding 1 ovule.[1] These are the cavities containing seeds within an ovary[10] Pseudopanax colensoi then produces fleshy fruits with a diameter of 4-6mm.[1] These fruits will turn dark purple, almost black, when ripe.[1] There are 2 seeds within each fruit that are shallowly wrinkled and 2.9-4.3mm long and rounded.[1]
Natural global range edit
Pseudopanax colensoi var. colensoi is native to New Zealand, and therefore is not found in other countries.[5] Many others in the Araliaceae family such as P. ferox, P. crassifolious, and P. arboretum are all native to New Zealand as well and do not grow elsewhere[11].
New Zealand range edit
Pseudopanax colesnoi var. colensoi is typically found ranging from the Central North Island and Coromandel Range down to the south of Banks Peninsula and potentially Dunedin on the South Island's east coast.[1] Generally, Pseudopanax arboretum grows more commonly; however, P. colensoi var. colensoi replaces it at the higher altitudes as it can handle those environmental conditions.[11] In the South Island, Pseudopanax colensoi grows in the North and East, stretching from Golden Bay to Dunedin, yet apparently it is absent from the West Coast.[11] Pseudopanax colensoi tends to grow further inland compared to P. arboretum and it inhabits the eastern half of the Buller River catchment.[11] In locations such as Mt Taranaki/Mt Egmont, it can grow up to 1200m in montane forest scrub and low subalpine scrub and can reach the subalpine belt in the South Island.[11] However, it is then taken over by the var. ternatum which has been documented at heights of up to 1,676m in Nelson.[11] The Nelson region is home to approximately 80% of all of New Zealand's alpine species making it one of the largest hotspots for alpine plant biodiversity[12].
Habitat edit
Pseudopanax colensoi thrives best in a habitat that has montane to low alpine forest and scrub conditions.[1] Due to these preferred conditions, Pseudopanax colensoi is challenging to find as it does not tend to grow on the traditional dry grassland plains of New Zealand. Generally, warmer areas are not suitable for its growth; however, P. colensoi could potentially establish in an exposed, dry, and semi-shaded site.[13] Pseudopanax spp. are most commonly found in native regenerating bush and along the edges of forests, specifically in lowland terrain.[11] As stated previously, Pseudopanax colensoi var. colensoi has not been found in the West Coast of New Zealand's South Island; however, the lush regenerative forests that the West Coast offers would be the ideal habitat for Pseudopanax colensoi if only a few environmental conditions were different.[11] The 'alpine zone' is generally referred to as the area between the upper limit of trees and the lower limit of consistent snowfall.[12] In New Zealand, the alpine area consumes approximately 11% of the country[12], extending on why Pseudopanax colensoi is much harder to come across compared to other congeners such as P. arboreus. Most of the 11% lies in the South Island due to vast mountain ranges such as the Southern Alps.[12] In the North Island, alpine landscape is restricted to the volcanoes of the central plateau such as Ruapehu, Mt Taranaki, Mt Egmont, Hikurangi and Ruahine.[12] This results in the North Island hosting a lower diversity of alpine plants compared to the South Island.[12] Whilst Pseudopanax colensoi does not grow in the highest alpine habitats, it still prefers subalpine conditions, meaning it grows best in cold, windy, and dry terrains. It can tolerate vast changes in temperature and can survive strong winds. It gets replaced by P. ternatum once the altitude gets too high, leaving P. colensoi to reach growth heights of 5-8m since it has some shelter from the harsh winds in the higher alpine region.[11]
Ecology edit
Life cycle/Phenology edit
Pseudopanax colensoi is a fast-growing tree/shrub that generally will reach a height of 5 meters and width of 2 meters, which it can surpass if left untouched and grown in its ideal habitat.[5] It flowers from October through March producing delicate, heavy- scented cream and green petals.[1] The plant then displays 4-6mm purple-black berries from October to March which are highly popular to birdlife.[1]
Growth Habitat edit
Typically, Pseudopanax colensoi var. colensoi grows best in montane to low alpine forest and scrub, meaning this plant thrives best in varying conditions from coastal to dry, frosty, rainy, and windy.[11] Montane habitats are located on the slopes of mountains, generally consisting of varying temperatures, dense to barren vegetation and frequently changing weather.[14] This area ranges in altitude from approximately 500 to 3500m, making it the ideal home for P. colensoi.[14] While most Pseudopanax species prefer free-draining soils, Pseudopanax colensoi can tolerate a vast range of conditions and soil types as well as various moisture amounts. However, it dislikes dry soils and tends to grow best in damper soil.[1] A montane forest is otherwise known as a 'cloud forest' due to its usual heavy rainfall and condensation from the constantly changing temperatures in the air.[14] Therefore, this habitat will usually have damp/wet soil and foliage, making it the ideal environment for Pseudopanax colensoi. If needed, the P. colensoi could survive in infertile soil or shattered rock, depending on the altitude.[12]
Predators, Parasites, and Diseases edit
Possums are known to eat this species, and in some cases cause severe damage to the populations numbers[1]. In some small cases, an insect known as the Pseudopanax leafminer weevil has been discovered leaving blotches along the leaves on Pseudopanax lessonii and Pseudopanax arborea.[15] These weevils have only been recorded in three locations, all within the Auckland region.[15] There are very few diseases that infect Pseudopanax. However, one common disease is Phytophthora ramorum (a fungal disease that causes root rot), to which P. crassifolius is susceptible.[16] A way to avoid this disease is ensuring the species is grown in dry, free-draining soil. Pseudopanax colensoi does have an advantage over the other Pseudopanax species as it prefers to grow in the low alpine conditions which are usually more inaccessible to browsing animals, giving this species the higher ground over its predators.
Other information edit
The history of the Pseudopanax colensoi name stems from a Cornish Christian missionary to New Zealand named William Colensoi (7th November 1811-10th February 1899), who was also a botanist, printer, politician, and explorer.[1] The name Pseudopanax simply means "false cure".[1] Due to the Pseudopanax spp. being rather versatile, it can be planted in various locations and withstand many differing environmental conditions.
References edit
- ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad "Pseudopanax colensoi var. colensoi". New Zealand Plant Conservation Network. Retrieved 26 March 2023.
- ^ "Dioecious". Merriam-Webster. Retrieved 28 March 2023.
- ^ "Petiolule". Merriam-Webster. Retrieved 28 March 2023.
- ^ "Stipule". Merriam-Webster. Retrieved 28 March 2023.
- ^ a b c d "Pseudopanax colensoi (Hook.f.) Philipson". BIOTA of New Zealand. Retrieved 27 March 2023.
- ^ "Coriaceous". Merriam-Webster. Retrieved 28 March 2023.
- ^ "Lamina". Merriam-Webster. Retrieved 28 March 2023.
- ^ "Umbel". Merriam-Webster. Retrieved 28 March 2023.
- ^ "Calyx". Merriam-Webster. Retrieved 28 March 2023.
- ^ "Locule". Merriam-Webster. Retrieved 28 March 2023.
- ^ a b c d e f g h i j Wardle, P (1968). "The taxonomy and distribution of the stipulate species of Pseudopanax in New Zealand". New Zealand Journal of Botany. 6 (2): 226–236. doi:10.1080/0028825x.1968.10429060. Retrieved 26 March 2023.
- ^ a b c d e f g "Alpine habitats". Department of Conservation. Retrieved 27 March 2023.
- ^ Cave, Yvonne; Paddison, Valda (2002). The Gardener's Encyclopaedia of New Zealand Native Plants. Auckland N.Z.: Random House New Zealand. p. 272.
- ^ a b c Doumenge, Charles; Gilmour, Don; Ruiz Perez, Manuel; Blockhus, Jill. "Tropical Montane Cloud Forests: Conservation Status and Management Issues". Tropical Montane Cloud Forests. 110: 24–37.
- ^ a b Martin, N. A. "Pseudopanax leafminer weevil - Pactola species 1". Interesting insects & other invertibrates. Retrieved 28 March 2023.
- ^ Huberli, D; Lutzy, B; Voss, B; Calver, M; Ormsby, M; Garbelotto, M (2008). "Susceptibility of New Zealand flora to Phytophthora ramorum and pathogen sporulation potential: an approach based on the precautionary principle". Australasian Plant Pathology. 37: 615–625. Retrieved 28 March 2023.