Leucadendron argenteum R.Br.

Silver tree (en)

Species

Angiosperms > Proteales > Proteaceae > Leucadendron

Characteristics

Trees up to 10 m high, with a stout trunk and thick bark. Branches erect, stout, few in number. Branchlets stout, densely adpressed-pubescent and villous, densely clothed with leaves. Leaves up to 15 cm long and 2 cm broad, lanceolate, semi-erect, narrowing to an acute mucronate apex, covered on both surfaces with an adpressed silvery pubescence, margins fringed with long hairs, distinctly veined. Male inflorescence 4 cm long, 5 cm diam., solitary, terminal, globose, surrounded and exceeded by the leaves, giving off a faint but pleasant smell. Basal bracts not numerous, ill defined in the transition from stem leaf to floral bract, not conspicuous, short-adpressed-pubescent, short-ciliate, sub-acute. Floral bracts 8 mm long, about 5 mm broad, ovate or ob-ovate, ciliate, short-adpressed-pubescent above and densely silky villous below, apex obtuse and purplish, narrowed to the base. Floral bud terete, not swollen, bent, glabrous below, short-silky-pubescent and coloured above. Perianth tube 8 mm long, glabrous. Claw 4 mm long recurved 270°, short-pubescent above. Limb 3 mm long, linear, coloured, adpressed-pubescent, concave, hooked. Anthers 2 mm long, sessile, linear, decumbent, stripped of pollen at anthesis. Pollen triangular with swollen apices in polar view, with sides 53 µ long, polar depth 26µ. Style 14 mm long, glabrous and narrowing above, pubescent below. Stigma abortive, 2 mm long, clavate, acting as a pollen presenter. Hypogynous scales 6 mm long, filiform, pale yellow, tapering, attached 1 mm above the base of the perianth. Nectar seen in the throat of the perianth tube at the apices of the hypogynous scales. Receptacle 2.5 cm long, 1 cm diam., clavate, obtuse. Female inflorescence 5 cm long, 4 cm diam., globose, solitary, terminal, surrounded and exceeded by the leaves, of a silvery or leaden hue with pinkish tones. Basal bracts about 2.2 cm long, 1.5 cm broad at the base, tapering, the acuminate upper half brown, tomentose, long-ciliate, about 41 cm number. Floral bract 1.5 cm long, 2 cm broad, orbicular, densely short-pubescent, ciliate. Floral bud 1.8 cm long, surrounded below by a dense tuft of hairs. Perianth tube 1.5 cm long, divided and densely villous above, connate and glabrous below. Claw 3 mm long, densely villous, recurved 90°. Limb 2.5 nm long, lanceolate, sub-acute, concave, slightly hooked, short-pubescent. Staminode 1.8 mm long, linear. Ovary 2 mm long, ovoid, densely pubescent. Style 1.5 cm long, filiform, glabrous, much thickened near the apex. Stigma 1.5 cm diam., suboblique, somewhat cleft. Hypogynous scales 2.5 mm long, stout, Pale yellow. Nectar not observed. Receptacle 4 cm long, 2 cm diam., clavate. Mature female head about 9 cm long, 6 cm diam., ovoid, apex somewhat acute, with bracts densely short-pubescent arranged in 3 ascending spirals. Fruit a nut, 1 cm long, 8.6 mm broad, 5.5 mm thick, biconvex, sparsely pubescent on the sides and below, dark brown, style and perianth persisting.
More
Dioecious tree to 10 m. Leaves lanceolate, adpressed-silvery hairy, fringed, to 150 mm long, involucral leaves similar. Male flower heads ± 50 mm diam., female ± 40 mm diam.
Life form perennial
Growth form tree
Growth support free-standing
Foliage retention evergreen
Sexuality dioecy
Pollination -
Spread -
Mature width (meter) 2.5 - 4.0
Mature height (meter) 7.0 - 9.0
Root system -
Rooting depth (meter) -
Root diameter (meter) -
Flower color
Blooming months -
Fruit color
Fruiting months -
Nitrogen fixer -
Photosynthetic pathway c3

Environment

Light 7-9
Soil humidity -
Soil texture 1-2
Soil acidity 2-6
Soil nutriment -
Hardiness (USDA) 10-12

Usage

Uses environmental use material medicinal
Edible -
Therapeutic use -
Human toxicity -
Animal toxicity -

Cultivation

Can be grown by cuttings.
Mode cuttings
Germination duration (days) -
Germination temperacture (C°) -
Germination luminosity -
Germination treatment -
Minimum temperature (C°) -
Optimum temperature (C°) -
Size -
Vigor -
Productivity -

Images

Flower

Leucadendron argenteum flower picture by Daniel Barthelemy (cc-by-nc)
Leucadendron argenteum flower picture by Daniel Barthelemy (cc-by-nc)

Distribution

Leucadendron argenteum world distribution map, present in Cook Islands, New Zealand, and South Africa

Conservation status

Leucadendron argenteum threat status: Vulnerable

Identifiers

LSID urn:lsid:ipni.org:names:704724-1
WFO ID wfo-0001106925
COL ID 6PSJH
BDTFX ID 83236
INPN ID -
Wikipedia (EN) Link
Wikipedia (FR)

Synonyms

Euryspermum argenteum Leucadendron argenteum Protea argentea