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Mitrasacme polymorpha

mitre weed

Loganiaceae Eastern and south-eastern Australia

Attracts Pollinators Container Friendly

SunFull Sun – Part Shade

WaterMedium

HardinessZones 9–10

Overview

Mitrasacme polymorpha is a slender, variable herb growing 2-12 inches (5-30 cm) tall, ranging from annual to short-lived perennial depending on conditions. Stems are thin, erect to spreading, and often wiry, branching from the base. Leaves are small, 0.1-0.4 inch (3-10 mm) long, narrow to oval, and arranged in opposite pairs or whorls along the lower stem, sometimes crowded into a basal cluster. Small white tubular flowers, about 0.1-0.2 inch (3-5 mm) long with four spreading lobes, are carried singly on thread-like stalks at the stem tips. Flowering occurs mainly in spring and summer. The fruit is a small two-parted capsule topped by two diverging beaks, the feature behind the common name mitre weed. As the species epithet suggests, leaf size, stem height, and growth form vary widely between populations and habitats. Plants grow in seasonally moist ground and may complete their life cycle quickly where soil dries out.

Native Range

Native to eastern and south-eastern Australia, including Queensland, New South Wales, Victoria, Tasmania, and South Australia, with related populations in New Caledonia and parts of South-East Asia. Grows in heath, sedgeland, open forest, and swamp margins in damp sandy or peaty soils.

Suggested Uses

Grown occasionally in native plant and bog-garden collections in damp, low-nutrient soil. Suited to seasonally wet sand or peat beds rather than general garden borders. Has no role in conventional ornamental planting.

How to Identify

Recognized by its slender wiry stems, small paired or whorled leaves crowded toward the base, and tiny white four-lobed tubular flowers 0.1-0.2 inch (3-5 mm) long on thread-like stalks. The two-beaked capsule at fruiting separates it from similar small herbs. Growth form varies from compact basal tufts to taller branched stems depending on habitat.

Appearance

Size & Dimensions

Height2" - 1'

Width/Spread2" - 6"

Colors

Flower Colors

white

Foliage Colors

green

Fall Foliage Colors

no change

Bloom Information

Bloom Period

~4 weeks

Spring Summer

Flowers mainly from September to February, with timing shifting by region and rainfall. Individual flowers are short-lived, but a plant produces flowers over several weeks. In drier sites flowering is compressed into a short period after rain.

Detailed Descriptions

Foliage Description

green

Growing Conditions

Sun Requirements

SunFull Sun SunPartial Shade

Requires 4-8 hours of direct sunlight daily

• Full Sun: 6+ hours of direct sunlight

• Partial Shade: 3-6 hours of direct sunlight

• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range4.5 - 6.5(Acidic)

357912

Soil Types

sand peat

Drainagemoist

Water & Climate

Water Needs

Medium

Frost Tolerance

hardy

Time to Maturity

1 year

Care & Maintenance

Care Guide

Grows in damp, low-nutrient sandy or peaty soils in open sunny to lightly shaded sites. Soil that stays seasonally moist supports longer growth, while rapid drying shortens the life cycle to a single season. The species is seldom cultivated and has no commercial nursery trade. Where grown in native plant collections, it needs an open, low-fertility medium and steady moisture during the growing season. Excess fertilizer and dense competition from larger plants reduce its persistence.