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Thelymitra peniculata

trim sun orchid

Orchidaceae Southeastern Australia

Attracts Pollinators

SunFull Sun

WaterLow

HardinessZones 8–10

Overview

Thelymitra peniculata is a terrestrial orchid growing from an underground tuber, producing a single erect flowering stem 8-24 inches (20-60 cm) tall. A solitary linear, channelled leaf 4-12 inches (10-30 cm) long emerges from the base each season. The stem carries 3-15 flowers, each 0.6-0.9 inch (15-22 mm) across, pale blue to mauve with darker veining. The column apex bears a dense tuft of white to cream hairs that separates this species from related sun orchids. Flowers open only in warm, sunny conditions and stay closed on overcast or cool days, which limits the time the open blooms can be seen. The plant is dormant through summer and autumn, persisting as a tuber below ground, and resprouts after autumn rains. It grows in seasonally moist woodland and heath on sandy or loamy soils. Like most Thelymitra spp., it depends on specific soil fungi for germination and establishment, making transplanting and cultivation difficult outside its natural range. Growth is slow, with seed-grown plants taking several years to reach flowering size.

Native Range

Thelymitra peniculata is native to southeastern Australia, occurring in Victoria, New South Wales, Tasmania, and South Australia. It grows in open forest, woodland, and heathland on seasonally moist sandy soils.

Suggested Uses

Grown in specialist native orchid collections and terrestrial orchid conservation plantings. It is not adapted to general garden borders or container culture because of its fungal dependency and summer dormancy.

How to Identify

Identify by the single linear, channelled leaf and an erect stem 8-24 inches (20-60 cm) tall bearing 3-15 pale blue to mauve flowers 0.6-0.9 inch (15-22 mm) wide. The column apex carries a dense tuft of white to cream hairs, the feature that gives the species its name. Flowers open only in warm sunlight, so plants are easily overlooked in dull weather when the blooms stay shut.

Appearance

Size & Dimensions

Height8" - 2'

Width/Spread4" - 8"

Colors

Flower Colors

Foliage Colors

Fall Foliage Colors

Bloom Information

Bloom Period

~3 weeks

Spring

Flowering occurs in spring, mainly October to November in its native range. Individual flowers open only on warm, sunny days and close in cool or cloudy weather. The display lasts about 2-4 weeks, though any single day may show few open flowers when conditions are unfavourable.

Detailed Descriptions

Flower Description

pale blue to mauve

Foliage Description

green

Growing Conditions

Sun Requirements

SunFull Sun

Requires 6-10 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 Range5.0 - 6.5(Acidic)

357912

Soil Types

sand loam

Drainagewell drained

Water & Climate

Water Needs

Low

Frost Tolerance

hardy

Time to Maturity

3-4 years from seed

Care & Maintenance

Care Guide

Thelymitra peniculata grows from a tuber in seasonally moist, well-drained sandy or loamy soil in full sun. It requires a mycorrhizal fungal association to germinate and establish, which makes cultivation outside its native habitat difficult. Plants need moisture through winter and spring growth, followed by a dry summer dormancy. Waterlogging during dormancy causes tuber rot. It is rarely grown in gardens and is most often seen in situ in protected bushland. Propagation is by seed sown with the appropriate fungus or by natural division of tubers.

Pruning

No pruning is required. The single leaf and flowering stem die back to the underground tuber after seed set, and the plant stays dormant until the following autumn. Spent stems can be left in place to release seed.