Welwitschia mirabilis ssp. namibiana Leuenb.

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.
Cone-bearing shoots dichasial, insect pollinated. Females subtended by cone-scales making up a red cone and consisting of a single 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 microsporangia subtended by cone-scalesmaking 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.

Culture: Difficult to cultivate requiring desert conditons and room to accomodate its long taproot. Propagated by seeds.
An excellent article by Anna Senters can be found here

Accession # 199700061
Source: Seed - UC-Davis, Univ of Colo. - Boulder
Accession Date: 09-18-1997
Bench: 2207 - XER:Namib / Karoo D
- Currently: active - healthy
- Qty: 4 confirmed on 11-13-2024
Restrictions:
- CITES Appendix II Listed Plant

This accession has been observed in bloom on:

The Plant Book, Mabberly, 1987
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, 13 Nov 2024 11:18:04 -0500 [bcm v4.0]

Plant Biodiversity Conservatory and Research Core