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Adding to the Rooibos page:

Life History and Reproduction

Aspalathus linearis has a slim endemic range in the wild, however cultivation techniques to maximize production have been effective at maintaining reproduction for consumption in correlation with the demand of the Rooibos tea industry.

The two pathways of response for Rooibos after a fire. Fynbos plants like A.linearis are fire dependent, however there are two different responses.

A. linearis is a legume and therefore an angiosperm that produces an indehiscent fruit. Its flowers make up a raceme inflorescence. Seed germination can be slow but sprouting can be induced with acid treatment. The seeds are hard shelled and often need scarification Like other members of the Genus,  A. linearis is  considered a part of the fynbos ecoregion, exclusive to the Cape Floristic Region, which can be dependent on fire for reproduction. It is often grouped with the honeybush, another fynbos plant from Southern Africa used for tea. For A.linearis, Fire can stimulate resprouting in the species, however this sprouting is less than in other fynbos plants. A. linearis can be considered facultative and obligate sprouters and have lignotuber development for after fires. Typically, there are two classifications of A. lineraris in response to fire: reseeders and resprouters. Reseeders are killed by fire, but the fire also stimulates the reestablishment via seeds. Resprouters are not killed during a fire, but resprout via the lignotubers established in the earth. Like most legumes, there is a symbiotic relationship between rhizoids and the underground lignotuber structure that promote nitrogen fixation and growth. The nitrogen content in the soil is an important environmental factor for growth, development and reproduction. It has been suggested that there are multiple ecotypes of A. linearis that have different selected methods of growth and morphology dependent on the environment. It is unclear how many ecotypes their might be given they limited geographic range, and the limited literature about genetic diversity. It has also been suggested that resprouting populations and reseeding populations have been selected for based on the environment as a way to reduce genetic bottlenecks, however it is unclear if this promotes certain reproductive strategies over others. Wild populations can contain both sprouting and non-sprouting individuals however cultivated rooibos are typically reseeders not resprouters and have higher growth rates. Cultivated A. linearis can be selected for to have certain traits that are desirable for human use. Cultivated plants are diploid with a base chromosome number of 9(2n=18 chromosomes) however there is limited understanding of how this might differ in ecotypes The selection process can include human mediated pollination, fire suppression, and supplementing soil contents.

Seeds of wild populations are dispersed by ant species. The use of ants as dispersers limits the amount of parent-offspring and sibling-sibling competition. Ants also are helpful in dispersion as they reduce the susceptibility of seeds to other herbivores. A. linearis is not found to be significantly pollinated by Cape honey bee’s like many other Fynbos plants suggesting an alternative way of primary pollination. It is likely that wasps play an important role in pollinating the flowers and some species are thought to be specially adapted to accessing the A. linearis flower.

Cape sugar bird on the head of a King Protea