Silver oak

Names and Synonyms

Common Names

• Silky Oak
• Australian silky-oak
• silk-oak
• silky-oak
• southern silky-oak
• Australian Silky Oak
• Australian Silver Oak
• Silver Oak
• Southern Silky Oak

Scientific Names

Accepted name

Synonyms

• Stylurus robustus
• Grevillea venusta
• Grevillea robusta var. compacta
• Grevillea robusta var. forsteri
• Grevillea umbratica

Regional and Traditional Names

Sources: Wikidata, Catalogue of Life

Taxonomical Classification

This plant belongs to the kingdom Plantae and the phylum Streptophyta, falling under the class Equisetopsida and subclass Magnoliidae. Within the order Proteales, it is classified under the family Proteaceae. Finally, its taxonomic identity is defined by the genus Grevillea.

Sources: The World Checklist of Vascular Plants (WCVP)

Distribution

This plant exhibits a diverse geographical distribution spanning several distinct regions. In Southeastern Europe, its presence can be noted within the country of Italy. It also inhabits parts of Macaronesia, specifically the Canary Islands and Cape Verde. Moving toward the African continent, it is found in West Tropical Africa, notably in Gambia. Finally, its range extends into West-Central Tropical Africa, where it is located in Cameroon.

Sources: The World Checklist of Vascular Plants (WCVP)

Botanical Identification

Ecology

The ecology of Grevillea robusta is characterized by its adaptability to various topographic gradients, primarily thriving in lowland habitats. It exhibits a broad elevational distribution, ranging from sea level (0 m AMSL) up to a maximum altitude of 1810 m AMSL. Within this vertical range, the species maintains a mean elevation of approximately 1500 m AMSL, allowing it to occupy diverse ecological niches across different altitudinal zones.

Elevational range max:

1810 m AMSL

Elevational range mean:

1500 m AMSL

Elevational range min:

0 m AMSL

Habitat :

Lowland

Genetics

The genetics of Grevillea robusta are characterized by a specific chromosomal architecture that defines its cellular structure and reproductive stability. The species possesses a diploid chromosome number, specifically $2n = 20$, which serves as a fundamental genetic marker for the taxon. This diploidy indicates a ploidy level of 2, meaning the plant maintains two complete sets of chromosomes within its somatic cells. This stable genomic configuration plays a crucial role in the inheritance of its various physiological and morphological characteristics, providing the genetic blueprint necessary for its development and adaptation.

Chromosome number :

20

Ploidy :

2

Life history

The life history of Grevillea robusta is characterized by its status as a perennial species, allowing it to maintain a long-term presence within its ecosystem. As a phanerophyte, the plant directs its growth upward, maintaining its photosynthetic organs on elevated woody stems that protect them from various environmental stressors. This life form is consistently categorized under the phanerophyte designation, reflecting its structural habit of growing as a large tree. Furthermore, the species exhibits an evergreen deciduousness, meaning it retains its foliage throughout the year without a seasonal shedding period, ensuring continuous metabolic activity and resource production.

Deciduousness :

evergreen

Life form :

phanerophyte

Lifecycle :

perennial

Morphology

The morphology of Grevillea robusta is characterized by a large, woody growth form, specifically categorized as a tree. As a terrestrial and independent organism, it does not function as an epiphyte or a parasite, maintaining a self-supporting structure rather than acting as a climber, liana, or vine. The plant exhibits significant vertical development, with a height range spanning from a minimum of 8 meters to a maximum of 40 meters, resulting in a mean plant height of approximately 24.67 meters.

Aquatic :

terrestrial

Climber :

self-supporting

Epiphyte :

terrestrial

Growth form :

tree

Parasite :

independent

Plant height max:

40 m

Plant height mean:

24.6666666666667 m

Plant height min:

8 m

Woodiness :

woody

Physiology

The physiology of Grevillea robusta is characterized by a C3 photosynthetic pathway, which dictates its carbon fixation processes and metabolic efficiency. The plant's foliage is organized in an alternate leaf arrangement, featuring pinnatifid leaf forms that vary significantly in size; specifically, the leaves typically range from a minimum length of 10 cm to a maximum of 34 cm, with widths spanning from 9 cm to 15 cm. Structurally, the plant does not exhibit succulence, indicating a lack of specialized water-storage tissues in its leaves. Regarding its nutrient acquisition and structural integrity, it does not function as a nitrogen fixer. Furthermore, the mechanical properties of its woody structure are reflected in a mean stem specific density (SSD) of 538 mg/cm³, providing the necessary physical support for its growth habit.

Leaf arrangement :

alternate

Leaf form :

pinnatifid

Leaf length max:

34 cm

Leaf length min:

10 cm

Leaf width max:

15 cm

Leaf width min:

9 cm

Nitrogen fixer :

no

Photosynthetic pathway :

C3

Stem specific density (SSD) mean:

538 mg/cm³

Succulence :

no

Reproduction

The reproduction of Grevillea robusta is characterized by a biotic pollination syndrome, specifically involving bats, which facilitates the fertilization of its orange-colored flowers. The flowering period typically begins in April and concludes in May, featuring inflorescences that range in length from a minimum of 0.07 m to a maximum of 0.12 m. Following pollination, the plant develops brown, dehiscent fruit categorized as a follicle. These fruits vary in size, with a length ranging from 1.5 cm to 2 cm. Each fruit contains a small number of seeds, typically between 1 and 10, with an average seed mass of approximately 0.0176105 g (varying from a minimum of 0.01007 g to a maximum of 0.083 g). The dispersal of these seeds follows an anemochorous syndrome, meaning they are dispersed by the wind. Notably, asexual reproduction is absent in this species, making sexual reproduction through its flowering and fruiting cycle the primary method of propagation.

Dehiscence :

dehiscent

Dispersal syndrome :

anemochorous

Flower colour :

orange

Flowering time :

Apr

Flowering time :

May

Fruit colour :

brown

Fruit length max:

2 cm

Fruit length min:

1.5 cm

Fruit type :

follicle

Inflorescence length max:

0.12 m

Inflorescence length min:

0.07 m

Pollination syndrome :

bat

Pollination syndrome :

biotic

Reproduction asexual :

absent

Seed mass max:

0.083 g

Seed mass mean:

0.0176105 g

Seed mass min:

0.01007 g

Seeds_per_fruit :

1-10

Sources: Global Inventory of Floras and Traits (GIFT)

Plant Parts

Grevillea robusta has 1 reported plant parts identified across 2 scientific publications and several other databases that are studied for medicinal purposes. The most consistently reported plant part include leaf.

Leaf

1. Journal of natural products
2. Science progress

Chemicals

Grevillea robusta has 8 reported phytochemicals identified across 2 scientific publications and several other databases. The most consistently reported chemicals include Dehydrobisgravillol, GRAVICYCLE, Graviphane, Methyldehydrograviphane, bisgravillol.

Dehydrobisgravillol

1. Journal of natural products

GRAVICYCLE

1. Journal of natural products

Graviphane

1. Journal of natural products

Methyldehydrograviphane

1. Journal of natural products

bisgravillol

1. Journal of natural products

dehydrogravicycle

1. Journal of natural products

dehydrograviphane

1. Journal of natural products

methylgraviphane

1. Journal of natural products

Preparations

Grevillea robusta has 2 reported preparations identified across 2 scientific publications and several other databases. The most consistently reported preparations include MeOH extract of the leaves, ethanolic leaf extracts.

Meoh extract of the leaves

1. Journal of natural products

Ethanolic leaf extracts

1. Science progress