Dense Crassula

Crassula colorata (Nees) Ostenf.

Synonyms - Tilleae colorata, Tilleae verticillaris, Tilleae acuminata.

Family: Crassulaceae.

Names:

Crassula is from the Latin crassus meaning thick and referring to the fleshy leaves and stems.
Dense Crassula refers to its densely packed leaves and flowers.

Other names:

Dense Stonecrop
Stonecrop

Summary:

A small, fleshy, erect, green to red, annual herb with densely packed leaves and flowers.

Description:

Cotyledons:

Two. About 1 mm and round to oval, pimply, fleshy with a rounded tip. Hairless.

First leaves:

Oval, fleshy, pimply with rounded tips. Hairless.

Leaves:

Opposite.
Petiole - None
Blade - Bright green when young to red/brown usually as it matures, oval, fleshy, pimply, 2-6 mm long x 1-4 mm wide, almost flat on one side and convex on the other, slightly and abruptly constricted near the base. Stem clasping and densely packed around the stem. Tip sub acute.

Stems:

Erect, sparsely branched, 15-150 mm tall, round, translucent with red centre. Hairless. Forms a mat on the ground.

Flower head:

Dense clusters in the leaf axils. All together forming a dense, leafy, interrupted spike.

Flowers:

White to pinkish, stalkless (or with very short stalk), bisexual, regular.
Ovary - Superior with a small, flat, pale yellow scale, 0.5-0.7 mm long, at the base.
Sepals - 5, egg shaped to triangular, 1-2.5 mm long, fleshy, striped, acute tip.
Petals - 5, pale yellow to red, lance to egg shaped, 1-2 mm long. Acute to cusped pink tip.
Stamens -
Anthers -

Fruit:

5, beaked, cylindrical, flattened, follicle that is usually warty (or pimply) on the lower half and longer than the sepals. 1-2 seeds per carpel. Seeds released by a basal split around the follicle.

Seeds:

Very small. Usually faintly ridged.

Roots:

Key Characters:

Flower parts 5; flowers spicate; Flowers in axillary clusters. Seeds 1-2 in each carpel.

Biology:

Life cycle:

Annual. Germinates anytime. Most productive in winter and spring. Flowers late-winter/spring

Physiology:

Reproduction:

By seed.

Flowering times:

Summer in SA.
Spring to summer in NSW.
Mainly August to October in Perth.

Seed Biology and Germination:

Vegetative Propagules:

Hybrids:

At least 2 varieties occur, one with smooth follicles (var. colorata) and one with tuberculate (pimply) follicles (var. tuberculata).

Allelopathy:

Population Dynamics and Dispersal:

Spread by seed.

Origin and History:

Australia.

Distribution:

ACT, NSW, NT, QLD, SA, VIC, WA.
Most parts of SA.

Courtesy Australia's Virtual Herbarium.

Habitats:

Climate:

Temperate to arid.

Soil:

Most soil types. Prefers sandy, loamy and shallow soils.

Plant Associations:

Wide range.
Common in dry sclerophyll woodlands.

Significance:

Beneficial:

Palatable fodder but does not produce much bulk.

Detrimental:

Weed of crops, disturbed areas and wet areas.

Toxicity:

Not recorded as toxic.

Legislation:

None.

Management and Control:

Thresholds:

Eradication strategies:

Herbicide resistance:

Biological Control:

Related plants:

Australian Crassula (Crassula. sieberiana) has 4 petals, larger cotyledons, narrower young leaves, is not pimply all over the plant, and is more compact in habit.
Dense Crassula (Crassula decumbens)
Three-parted Crassula (Crassula alata)
Swamp Crassula (Crassula helmsii)
Crassula ciliata
Crassula glomerata
Crassula multicava
Crassula natans
Crassula tetragona

Plants of similar appearance:

Chickweed (Stellaria media)
Corn Spurrey (Spergula arvensis)
Four-leaved Allseed (Polycarpon tetraphyllum)
Mouse-eared Chickweeds (Cerastium spp.)
Pearlwort (Sagina apetala)
Pimpernel (Anagallis arvensis)
Waterblinks (Montia spp.)
Pigweed (Portulaca spp.)

References:

Black, J.M. (1965). Flora of South Australia. (Government Printer, Adelaide, South Australia). P391. Diagrams.

Burbidge, N.T. and Gray, M. (1970). Flora of the Australian Capital Territory. (Australian National University Press, Canberra). P190.

Cunningham, G.M., Mulham, W.E., Milthorpe, P.L. and Leigh, J.H. (1992). Plants of Western New South Wales. (Inkata Press, Melbourne). P340. Photo.

Gilbey, D. (1989). Identification of weeds in cereal and legume crops. Bulletin 4107. (Western Australian Department of Agriculture , Perth). P57.

Lamp, C. and Collet, F. (1990). A Field Guide to Weeds in Australia. (Inkata Press, Melbourne). p???.

Lazarides, M. and Hince, B. (1993). CSIRO handbook of economic plants of Australia. (CSIRO, Melbourne). #366.3.

Marchant, N.G., Wheeler, J.R., Rye, B.L., Bennett, E.M., Lander, N.S. and Macfarlane, T.D. (1987). Flora of the Perth Region. (Western Australian Herbarium, Department of Agriculture, Western Australia). P205.

Wilding, J.L. et al. (1987). Crop weeds. (Inkata Press, Melbourne). P98. Diagrams. Photos.

Acknowledgments:

Collated by HerbiGuide. Phone 08 98444064 or www.herbiguide.com.au for more information.