Australian Tropical Rainforest Plants - Online edition

Xanthostemon paradoxus F.Muell.


Tree
Click/tap on images to enlarge
Flowers. © Australian Plant Image Index (APII). Photographer: M. Fagg.
Fruit. © Australian Plant Image Index (APII). Photographer: J. Wrigley.
Scale bar 10mm. © CSIRO
10th leaf stage with cotyledons present. © CSIRO
Cotyledon stage, epigeal germination. © CSIRO
Family

Mueller, F.J.H. von in Hooker, W.J. (1857) Hooker's Journal of Botany & Kew Garden Miscellany 9 9: 17. Type: Northern Territtory, Sea Range, Victoria River, Dec. 1855, F. Mueller; lecto: MEL 63369.

Common name

Bridal Tree; Northern Penda; Penda, Northern

Stem

Cream or pale, brittle stripes usually visible in the outer blaze.

Leaves

Leaf blades about 5-16 x 3-6 cm. Lateral veins curving but not forming definite loops inside the blade margin. Oil dots visible with a lens. Midrib grooved on the upper surface.

Flowers

Calyx tube (hypanthium) pubescent, about 2-2.5 x 5-5.5 mm, lobes pubescent, about 2-2.5 mm long, marked by oil glands. Petals pubescent, +/- orbicular, about 4-5 mm diam., marked by oil glands. Staminal filaments bright yellow, about 7-10 mm long, each inserted in an orifice in the base of the anther, anthers about 1.5 mm long. Ovary surrounded by and half enveloped in the calyx tube (hypanthium). Ovary glabrous, about 2 mm diam., placentas peltate. Style yellow, about 25 mm long. Stigma small and terminal.

Fruit

Fruits globular or depressed globular, about 10 x 12 mm, calyx persistent at the base. Seeds flat, about 2-4 mm diam. Embryo +/- orbicular, about 1.5-2 mm diam. Radicle straight.

Seedlings

Cotyledons reniform to almost orbicular, about 6-7 x 6-10 mm. Oil dots numerous, easily seen with a lens. At the tenth leaf stage: leaf blade elliptic to obovate, apex acute, base attenuate or cuneate, upper and lower surfaces clothed in long, white hairs; oil dots large, visible to the naked eye; petiole, stem and terminal bud densely clothed in long, silky, white hairs. Seed germination time 9 to 14 days.

Distribution and Ecology

Endemic to Australia, occurs in WA and NT. Altitudinal range from sea level to 250 m. Generally grows in open forest or on rocky hillsides but sometimes found in monsoon forest or on its margins.

Natural History & Notes

A species commonly cultivated in the Darwin area for its shady habit and the large bunches of yellow flowers which attract birds.

Synonyms
Metrosideros paradoxus (F.Muell.) F.Muell., Fragmenta Phytographiae Australiae 1: 243(1858). Nania paradoxa (F.Muell.) Kuntze, Revisio Generum Plantarum 1: 242(1891).
RFK Code
973
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