Welwitschia mirabilis ssp. namibiana Leuenb.
- Common Name: Tree Tumbo
- Family: Welwitschiaceae Markgraf.
- Synonym(s): Welwitschia bainesii (Hook.f.) Carrière
- Country of Origin: Namib Desert
- Description: A single species of dioecious perennial with short stem and taproot native to S. Angola and SW African deserts, extending into mopane woodland. It is a long-lived plant, deriving moisture from sea-fog dew. Winged seeds germinate in wet years, the cotyledons photosynthesizing for 1.5 years; foliage leaves decussate with respect to cotyledons, of indefinite growth (up to 13.8 cm per year), wearing away at the tips, the apical meristem being lost. Fertile buds are produced on the 'crown' between the leaf bases.
Reproductive shoots dichasial, insect pollinated. Females subtended by cone-scales making up a red cone and consisting of a nucellus enclosed in an integument and another layer derived from two confluent primordia ('calyx and corolla of a flower (generally used when the two are similar).">perianth') with 2 'bracts'; megaspore mother-cell grows into a prothallus without archegonia. Male pollen-bearing structures subtended by cone-scales making up a red cone and consisting of 2 lateral 'bracts' and a 'perianth' formed by the union of 2 bract-like organs, 6 microsporangiophores and a sterile unitegmic ovule; male gametophyte merely a tube-nucleus, an abortive sterile cell and a cell giving rise to 2 sperm nuclei. As pollen tubes penetrate prothallus, prothallial tubes grow up to meet them in the nucellus, fusion of females and males allegedly occurring in the tubes; many zygotes but only one matures and is dispersed with 'perianth' as a wing.
Somewhat challenging in cultivation; appreciating warmth, strong sun, large pots, and more water than might be expected. Never allow soil to dry completely. Propagated by seeds.
- Culture: An excellent article by Anna Senters can be found here
Accession Data:
Classification:
- Division: Gnetophyta
- Class: Gnetopsida
- SubClass: Gnetidae
- Order: Welwitschiales
- SubOrder:
- Family: Welwitschiaceae
- SubFamily:
- Tribe:
- SubTribe:
Flowering Data:
This accession has been observed in bloom on:
Year | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
2024 |
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2023 |
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2022 |
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2021 |
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2020 |
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2019 |
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2018 |
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2017 |
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2016 |
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2015 |
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2014 |
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2013 |
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2012 |
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2011 |
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References (internal):
References (external):
- The Plant Book, Mabberly, 1987
- Photos 3 & 4 courtesy Dr. John Silander, EEB, July 2004 - all rights reserved.
- The Plant List (2013). Version 1.1. Accessed 26 February 2015.
- WCSP (2015). World Checklist of Selected Plant Families. Facilitated by the Royal Botanic Gardens, Kew. Accessed 26 February 2015.
- Senters, Anna E., Welwitschia mirabilis cultivation in AERGC Newsletter, Vol 10 (2), Summer 1997 p.5-7. Last accessed on Monday, January 23, 2017.
- Welwitschia Propagation at Burger's Onion (Matt's blog). Last accessed on Wednesday, December 20, 2017.
data regenerated on Wed, 31 Jul 2024 15:51:02 -0400 [bcm v4.0]