Livistona rigida

Livistona (liv-iss-TOH-nah) rigida (rih-GEE-dah)
Livistona rigida, Island Stack, Lawn Hill Gorge, Boodjamulla National Park, QLD, 24/08/05. Photo by Russell Cumming.
Scientific Classification
Genus: Livistona (liv-iss-TOH-nah) Species: rigida (rih-GEE-dah)
Synonyms
None set.
Native Continent
Oceania
Morphology
Habit: Solitary Leaf type: Costapalmate
Culture
Survivability index
Common names
Mataranka Palm, Lawn Hill Gorge Livistona, Gregory R. Cabbage Palm.

Habitat and Distribution

Australia. Queensland and Northern Territory.

Livistona rigida and Melaleuca fluviatilis, Island Stack, Lawn Hill Gorge, Boodjamulla National Park, QLD, 24/08/05. Photo by Russell Cumming.

In north-western Queensland in the catchments of the Gregory, Leichhardt, Nicholson, Albert and Flinders Rivers, and in the Northern Territory on the Roper R., South Alligator Rivers and east Arnhem Land. Grows as a riparian element along stream margins, on seasonally inundated banks, in creek lines and watercourses, sometimes with intermittent flow, but with a permanent shallow water supply, 2-300 m alt.

This species, which is closely related to L. mariae, is found at the Mataranka Hot Springs Reserve and along the Roper River as well as in scattered groups along rivers of the Gulf of Carpentaria. It is also found as scattered remnants in open forest indicating a previous more widespread distribution. Reed states the species extends along the Roper River from Mataranka to Elsey, about 70-80 km, being densest in the Red Lily Lagoon area. It also extends a short distance along some of the tributaries such as Salt Creek and Elsey Creek.

Description

Functionally dioecious palm. Trunk to 28 m tall, 30-40 cm in diam. breast high, leaf scars raised, internodes narrow, grey, petiole stubs persistent in the basal 1 m or so, otherwise deciduous. Leaves 30-50 in a globose crown; petiole 150-250 cm long, 20-35 mm wide, adaxially concave, margins with single curved reddish-black spines to 6 mm long in the proximal portion, otherwise smooth; leaf-base fibres moderately prominent, coarse, persistent; lamina costapalmate, regularly segmented, circular in outline, 125-170 cm long, 100-150 cm in diam., rigidly coriaceous, adaxially grey to glaucous, midgreen, semi-glossy, abaxially lighter green, glaucous; lamina divided for 50-55% of its length, with 50-78 segments, depth of apical cleft 30-63% of the segment length, apical lobes acuminate, rigid or semi-pendulous; parallel veins 5-7 each side of midrib; transverse veins thinner than parallel veins. Inflorescences unbranched at the base, not sexually dimorphic, 100-250 cm long, not extending beyond the limit of the crown, branched to 4 orders; artial inflorescences 9-14; prophyll 25-38 cm long, 8-9 cm wide; peduncular bract 1, loosely tubular with moderate to dense white-grey scales; rachis bracts loosely tubular with sparse white scales; rachillae 3-8 cm long, rigid, glabrous. Flowers in clusters of 3-8, globose, about 1.8 mm long, cream to yellow; sepals broadly ovate, about 2 mm long, thin, acute; petals triangular 1.0-1.4 mm long, obtuse; stamens about 1.2 mm long. Fruit globose, 12-14 mm in diam., semi-glossy black; epicarp with scattered lenticellular pores; suture line extends for about ½ the length of the fruit, marked with lip-like tructures; mesocarp fibrous; endocarp thin; pedicel about 2 mm long. Seed globose, 9-11 mm wide. Eophyll 5-ribbed. (Dowe, J.L.)/Palmweb.

Culture

Less cold tolerant than L. mariae.

Seeds planted in deep trays will germinate freely in a few weeks, but nothing will appear above ground for 2 or 3 months. The seedbox should be placed in the sun at this point and kept well watered. Seedlings are moved to progressively larger pots, moderately fertilized and a course mix used. To prevent fungus attacks plants should be kept in full sun and plenty of wind, but very well watered. It has bronzed leaves for its life in pots, and retains this coloration a further 2 or 3 years after planting out. Although often available in nurseries, it is perhaps a little too big for suburban gardens. (Palms & Cycads)

Comments and Curiosities

Phenology: Flowers Jun-Dec; fruits Nov-May.

"In Palm Valley they grow densely along the creek. I first went there in my teens and remember being told they were special as their nearest living relatives were the Cabbage Palms on the east coast, Livistona australis. It was a very remote area and the only information around was via word of mouth. The palms were considered a relict population from a time when the centre of the continent was wetter. There were Melaleucas there as well, also associated with wet climates." (tropicbreeze)

"Livistona rigida is variable with redness. In habitat they grow in full sun, stronger than Florida or Arizona, but you still get red or green individuals as small plants. A number of other Livistonas are just as sun hardy, humilis, inermis, victoriae, alfredii, etc." (tropicbreeze)