Origin, provenance and genetics: three different scales in plant selection

Origin, provenance and genetics describe different scales. Origin indicates whether or not a species is native to a territory; provenance identifies where the plant material came from; genetics refers to the diversity and characteristics within the species or cultivar. Confusing these levels makes contracts, reservations and decisions about adaptation unclear.

Native status is defined for a geographical area and should be checked in botanical sources. A species may be native to Portugal and rare or absent in the specific region of the project.

This scale helps in assessing ecological relationships and fit with the landscape, but it does not tell you where the batch supplied came from.

Two trees of the same species may have been propagated from populations in different climatic regions. Provenance can influence phenology, tolerance and adaptation, especially in forest species.

In supply, traceability should state the grower, the propagation method and, where relevant, the origin of the material.

A cultivar selects particular characteristics and can reduce variability within the batch. This is useful for uniformity of form, but it can increase vulnerability when the same selection is repeated on a large scale.

In biodiversity or restoration projects, greater genetic diversity may be desirable. In formal avenue plantings, uniformity may carry more weight. The decision should be explicit.

In tenders and nursery reservations, the specification can separate botanical name, cultivar, propagation method and required provenance. When genetic origin is not critical, a vague requirement that is impossible to verify should be avoided. When it is critical, traceability needs to be requested from the outset.

Uniformity also has to be decided. An avenue planting may need trees that are similar in form, while a woodland may benefit from variation. Genetics should answer to the design and the risk, not to a general rule.

The most common mistakes are using ‘local’ without defining distance or provenance; assuming that a Portuguese nursery means Portuguese genetics; confusing cultivar with species; and repeating clones across an entire urban network.

At Diaplant, origin, provenance and cultivar are recorded separately whenever they influence performance or traceability. This distinction is especially important in reservations, contracts and contract growing.

Separating the three scales improves both purchasing and design. The question is no longer just ‘which species?’ and comes to include ‘where does this material come from and how much diversity does it represent?’.

• Flora-On — Flora de Portugal interativa. Sociedade Portuguesa de Botânica. (2025).
• Forest Research. Urban Tree Manual. (2018).
• Forest Research. Urban forests — climate change advice. (2026).