Montia fontana L.
Montia commemorates Giuseppe Monti (1682-1760) who was Professor of Botany at Bologna.
Summary:A hairless, small, prostrate annual herb with paired leaves forming a loose untidy rosette like clump. Young plants are semi erect.
Two, 4-8 mm long, somewhat succulent with a petiole 4-8 mm long. Hairless. The seedling has a short hypocotyl and a short epicotyl though this may not develop until the seedling has grown beyond the two leaf stage. Tip rounded. Sides convex. Base tapered. Surface hairless
First leaves: The early leaves have a blade 4 to 8 mm long with a petiole about the same length or rather longer, are hairless and are somewhat succulent in appearance.
Leaves: Paired and at right angles to the pair below. Form a loose, untidy, rosette like clump.
Stipules - None.
Petiole - Short or absent. Hairless.
Blade - Spade shaped to elliptical, 5-15 mm long, with no midrib groove. Hairless.
Stem leaves - 15 mm long with a short or no petiole.
Stems: Branch from the base, slender, up to 20-200 mm long, solid, circular in cross-section, soft, weak. Hairless and smooth. Roots at the lower nodes. Young stems are semi erect but become prostrate as they grow longer.
Flower head:Small cymes, terminal or in upper leaf axils, occasionally single flowers. Flowers on short stalks
Flowers: 1-2 mm diameter.
Ovary - Superior, 3 ovules. Style with 3 branches.
Sepals - 2, broad and flat topped to circular, persistent, 1 mm long.
Petals - White, tubular with 5 lobes, split open on one side. Slightly longer than the sepals.
Stamens - 3-5, attached at the top of the petal tube.
Anthers - Opening longitudinally on the inside (introrse).
Fruit:Globular capsule with 3 seeds, opening in 3 valves.
Seeds:Black, almost globular with concentric rows of tiny warts (tubercles).
Roots:Taproot with fibrous roots from a lower stem nodes.
Key Characters:5 lobed corolla. Tufted stems. White flowers with pedicels. Leaves and stems not succulent. Opposite leaves at right angles to the pair below. Annual. Anthers introrse.
Annual herb. Germination occurs in autumn and to a lesser extent in spring.
Flowering times:September to December.
Seed Biology and Germination:Vegetative Propagules:
Stems roots at the nodes and may form daughter plants.
Hybrids:Subspecies chondrosperma has 1 mm seeds with blunt or flat topped tubercles spread over the whole surface.
Subspecies amporitana has seeds less than 1 mm diameter and the tubercles around the keel are conical.
Allelopathy:Population Dynamics and Dispersal:
Spread by seed.
Origin and History:Australia.
Distribution:ACT, NSW, SA, TAS, VIC.
Montia occurs in all parts of Tasmania, and is more common in the North than in the South.
Courtesy Australia's Virtual Herbarium.
Plant Associations:Wetland plants.
Detrimental:A weed of wet areas and crops but it is of little or no economic importance.
Toxicity:Not recorded as toxic.
Management and Control:Thresholds:
Generally doesn't cause significant yield depressions.
Eradication strategies:Herbicide resistance:
White Purslane (M. australasica).
Plants of similar appearance:Seedlings resemble Chickweed (Stellaria media) Montia is hairless, has no mid-rib groove on leaves and a broader petiole.
Mouse-eared Chickweed (Cerastium spp.) has hairy leaves
Scarlet Pimpernel (Anagallis arvensis) has a kite-shaped cotyledon with a short merging petiole and sessile leaves.
Australian Crassula, Dense Crassula, Spreading Crassula (Crassula spp.)
Chickweed (Stellaria media)
Four-leaved Allseed (Polycarpon tetraphyllum)
Mouse-eared Chickweeds (Cerastium spp.)
Pearlwort (Sagina apetala)
Pimpernel (Anagallis arvensis)
Pigweed (Portulaca spp.)
References:Black, J.M. (1965). Flora of South Australia. (Government Printer, Adelaide, South Australia). P350-351. Diagram.
Burbidge, N.T. and Gray, M. (1970). Flora of the Australian Capital Territory. (Australian National University Press, Canberra). P161.
Hyde-Wyatt, B.H. and Morris, D.I. (1975). Tasmanian weed handbook. (Tasmanian Department of Agriculture, Hobart, Tasmania). P90-91. Diagram.
Lamp, C. and Collet, F. (1990). A Field Guide to Weeds in Australia. (Inkata Press, Melbourne).
Lazarides, M. and Hince, B. (1993). CSIRO handbook of economic plants of Australia. (CSIRO, Melbourne) #843.2.
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