Stelis spp.

leach orchids

Orchidaceae

Neotropics (Mexico, Caribbean, Central and South America, especially the Andes)

Attracts Pollinators Container Friendly

Native to North America

SunPart Shade – Full Shade

WaterMedium

HardinessZones 10–11

Overview

Stelis spp. is a large genus of more than 500 small epiphytic orchids in the family Orchidaceae, native to the Neotropics and most diverse in the cool, humid montane forests of the Andes. Plants grow as tufts of thin stems, each 1 to 8 in (2.5 to 20 cm) tall and topped by a single leathery, paddle-shaped leaf. From the leaf base rises a wiry spike carrying many tiny flowers along its length. The flowers are dominated by three triangular sepals, often translucent, while the petals and lip stay minute; sepal color spans green, yellow, white, red, and purple, sometimes with darker spotting. Many species hold their sepals partly closed, so the flowers read as small three-pointed cups. Plants attach to tree bark and mossy branches by fleshy roots and draw moisture from rain and cloud rather than from soil. The genus is grown by orchid specialists mounted on bark or in small pots of open mix. Limitations include the very small flower size, a need for steady humidity and cool to intermediate temperatures, and intolerance of drying out or heat.

Native Range

Stelis spp. ranges through the Neotropics from Mexico and the Caribbean south through Central America to Bolivia and Brazil. The genus reaches its greatest diversity in the Andean cloud forests of Colombia, Ecuador, and Peru. Plants grow as epiphytes on trees and, less often, on mossy rocks at mid to high elevations.

Suggested Uses

Stelis spp. is grown by orchid hobbyists and in botanical collections, mounted on bark or cork or potted in small containers in a humid, shaded case or greenhouse. The compact tufts suit terrariums and orchidariums. Plants are kept as windowsill orchids where humidity can be held high.

How to Identify

Identify Stelis spp. by its dense tufts of slender stems, each bearing one leathery leaf, and by the wiry spikes of many small flowers built around three triangular sepals. The petals and lip are minute and partly hidden between the sepals, so each flower reads as a tiny three-pointed star or cup. Flower color ranges from green and yellow to red and purple, often translucent.

Appearance

Size & Dimensions

Height1" - 8"

Width/Spread2" - 8"

Colors

Flower Colors

red

Foliage Colors

Fall Foliage Colors

Bloom Information

Stelis spp. species flower mainly in autumn and winter, though some bloom more than once a year and a few flower over many months. Each spike opens its many small flowers in succession over several weeks. The flowers are pollinated by small flies and gnats drawn to the close-set sepals.

Detailed Descriptions

Flower Description

green, yellow, white, red, or purple

Foliage Description

green to dark green

Growing Conditions

Sun Requirements

SunPartial Shade SunFull Shade

Requires 2-6 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 Range5.5 - 6.5(Neutral)

357912

Soil Types

peat

Drainagewell drained

Water & Climate

Water Needs

Medium

Frost Tolerance

tender

Time to Maturity

2-4 years to flowering size

Care & Maintenance

Care Guide

Stelis spp. grows in bright shade with steady humidity above 60 percent and cool to intermediate temperatures, reflecting its montane cloud-forest origins. Plants are mounted on bark or grown in small pots of free-draining fir bark or sphagnum, and roots are watered often enough that they never dry out fully between waterings. Most species decline in heat above 85 F (29 C) and in dry air, which shrivels the leaves and stems. They are frost tender and grown indoors or under glass outside the tropics. Light feeding at quarter strength during active growth suits the small root systems. Steady air movement reduces rot in the dense tufts.

Pruning

Stelis spp. needs no routine pruning. Spent flower spikes are removed once the last flowers drop, and dead leaves and stems are trimmed from the tuft to keep it open. Plants are divided only when a clump outgrows its mount or pot.