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

USDA Zone: 9-11

Accession Data:

Accession # 201100223
Source: Joe Lamacchia (swap for some 199700061)

Provenance:

These plants came in trade from Joseph Lamela-Macchia of New Jersey; a new accession number was added in 2011. There are two larger original plants in this accession: a female from Cactus Data Plants and a male from Grigsby Cactus Gardens.

Accession Date: 07-12-2011
Bench: 2207 - XER:Namib / Karoo D
- Currently: active - healthy
- Qty: 2 confirmed on 04-08-2025
Restrictions:
- CITES Appendix II Listed Plant

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
2025
2024
2023
2022
2021
2020
2019
2018
2017
2016
2015
2014
2013
2012
2011

References (internal):

EEB Greenhouse Holdings native to: Angola / Namibia

References (external):

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 Thu, 29 May 2025 10:45:02 -0400 [bcm v4.0]

Plant Biodiversity Conservatory and Research Core

Accession Data:

Welwitschia mirabilis ssp. namibiana Leuenb.

Accession Data:

Classification:

Flowering Data:

References (internal):

References (external):

Images:

Additional images for this accession:

Current Accessions in the Welwitschiaceae