Oxalis Triangularis vs Rex Begonia Plant Comparison

Compare these two plants side by side — care needs, key differences, and which is right for your home.

Oxalis Triangularis

Oxalis Triangularis

Oxalis triangularis

VS
Rex Begonia

Rex Begonia

Begonia rex

Oxalis Triangularis

Oxalis Triangularis

Oxalis triangularis

Oxalis triangularis is a rhizomatous perennial plant known for its striking, triangular, purple leaves that resemble shamrocks. The leaves fold up at night and reopen during the day in response to light, a phenomenon called nyctinasty. It produces small, trumpet-shaped white or pale pink flowers. It's primarily grown as an ornamental plant, both indoors and outdoors in warmer climates, for its unique foliage and interesting movement. While it can be grown indoors, it thrives with ample bright light.

Oxalidaceae Brazil
✨ Features: Nyctinastic movement (leaves fold up at night), striking purple foliage.
📖 Read Complete Oxalis Triangularis Guide
Rex Begonia

Rex Begonia

Begonia rex

Rex Begonias are prized for their spectacularly colored and textured leaves, rather than their flowers. They are rhizomatous perennials, meaning they grow from thick, modified stems that creep along the soil surface. These plants are primarily grown as ornamentals for their foliage, which exhibits a wide range of colors, patterns, and textures. While they can be grown indoors, they require specific conditions to thrive and are not always the easiest houseplants. They are popular for adding a vibrant splash of color to shaded gardens or as container plants.

Begoniaceae Assam region of India
✨ Features: Striking foliage with a wide range of colors, patterns, and textures.
📖 Read Complete Rex Begonia Guide

Quick Plant Comparison

Feature Oxalis Triangularis Rex Begonia
Light Bright indirect light to partial sun. Requires at least 4-6 hours of bright indirect light daily to maintain vibrant color and prevent legginess. Bright, indirect light. Avoid direct sunlight, which can scorch the leaves.
Watering Every 7-10 days, depending on environmental conditions Every 7-10 days, depending on environmental conditions.
Humidity 40-60% 50-60%
Temperature 18-24°C 18-24°C
Care Level Easy Moderate
Growth Rate Moderate Moderate
Max Height 30-45 cm 30-45 cm
Pet Safety ❌ Toxic To Pets ❌ Toxic To Pets
Soil Well-draining potting mix, such as a mix of peat moss, perlite, and vermiculite. Well-draining potting mix, such as a mix of peat moss, perlite, and vermiculite.
Beginner Friendly ✅ Yes With Caution
Weekly Maintenance 5-10 minutes weekly 10-15 minutes weekly

🔬 Botanical Information — Comparing These Plants

Oxalis Triangularis

Scientific Name Oxalis triangularis
Family Oxalidaceae
Native To Brazil
Also Known As Purple Shamrock, False Shamrock, Love Plant
Leaves The leaves are triangular in shape, resembling shamrocks. They are typically a deep purple color, although some varieties have green or variegated leaves. The leaves are smooth and delicate, with three leaflets arranged in a triangular pattern. They range from 2-5 cm in size.
Flowers Oxalis triangularis can flower indoors, especially when provided with adequate light. The flowers are small, trumpet-shaped, and typically white or pale pink. They appear on slender stems above the foliage and add a delicate touch to the plant.

Rex Begonia

Scientific Name Begonia rex
Family Begoniaceae
Native To Assam region of India
Also Known As Rex Begonia, Painted-Leaf Begonia, Fancy-Leaf Begonia
Leaves The leaves of Rex Begonias are large, often asymmetrical, and come in a wide range of colors, including shades of green, red, pink, purple, silver, and brown. They can be smooth, textured, or ruffled, and often feature intricate patterns and variegation. Leaf size can vary depending on the cultivar, but they typically range from 10-20 cm in length.
Flowers Rex Begonias do produce flowers, but they are relatively insignificant compared to the foliage. The flowers are typically small, pink or white, and are often removed to encourage more vigorous leaf growth. Flowering is rare indoors.

📏 Size & Growth — Plant Comparison

Oxalis Triangularis

Height 30-45 cm
Spread 30-45 cm (spreads via rhizomes)
Growth Rate Moderate
Growth Pattern Oxalis triangularis grows in a bushy, upright manner. It emerges from rhizomes, producing multiple stems with triangular leaves. The plant can spread via rhizomes, gradually filling the pot over time.

Rex Begonia

Height 30-45 cm
Spread 30-60 cm (spreads via rhizomes)
Growth Rate Moderate
Growth Pattern Rex Begonias grow from rhizomes, which are thick, modified stems that creep along the soil surface. New leaves emerge from the rhizomes, creating a bushy, spreading plant. They do not typically climb or trail.

🌱 Propagation — Comparing Plant Growth

Oxalis Triangularis

Methods: Division, Rhizome cuttings, Seed

Difficulty: Easy

Tips: Divide rhizomes during repotting. Plant rhizome cuttings in well-draining soil and keep moist until new growth appears. Seeds can be sown in spring.

Rex Begonia

Methods: Leaf cuttings, Rhizome cuttings, Division

Difficulty: Moderate

Tips: For leaf cuttings, make small slits in the veins on the underside of the leaf and place it on moist potting mix, weighing it down slightly. For rhizome cuttings, cut a section of rhizome with a leaf attached and plant it in moist potting mix. Division involves separating the rhizome into smaller sections, each with roots and leaves.

✨ Benefits & Features — Comparing Plant Value

Oxalis Triangularis

The most unique characteristic is the nyctinastic movement of its leaves, folding up at night and opening during the day. The striking purple, triangular foliage also sets it apart from many other houseplants. It's a relatively fast-growing plant that can quickly fill a pot.

  • ✓ Adds a pop of color to any room.
  • ✓ Provides a unique and interesting visual display with its moving leaves.
  • ✓ Relatively easy to care for, making it suitable for beginners.
  • ✓ Can be easily propagated and shared.
  • ✓ Offers a touch of whimsy and natural beauty to indoor spaces.
  • ⚠️ Toxic to pets

Rex Begonia

Rex Begonias are known for their incredibly diverse and colorful foliage. No two leaves are exactly alike, and the variations in color, texture, and pattern are truly remarkable. Their rhizomatous growth habit also sets them apart from many other houseplants.

  • ✓ Adds vibrant color and visual interest to indoor spaces.
  • ✓ Relatively easy to propagate, allowing you to expand your collection.
  • ✓ Can help improve indoor humidity levels (though it needs high humidity itself).
  • ✓ Offers a wide variety of leaf patterns and colors to choose from.
  • ✓ Provides a sense of accomplishment when successfully grown.
  • ⚠️ Toxic to pets

📅 Maintenance Schedule — Plant Care Comparison

Oxalis Triangularis

Repotting Every 1-2 years, or when the plant becomes root-bound. Divide rhizomes during repotting to propagate.
Pruning Remove dead or yellowing leaves to maintain appearance and prevent disease.
Fertilizing Balanced liquid fertilizer (10-10-10) diluted to half strength, every 4-6 weeks during the growing season (spring and summer).
Seasonal Care Reduce watering in fall and winter as the plant may go dormant. Provide bright light during the growing season (spring and summer).

Rex Begonia

Repotting Repot every 1-2 years in the spring, or when the plant becomes root-bound. Choose a pot that is slightly larger than the previous one.
Pruning Remove any dead or damaged leaves to encourage new growth. Pinch back stems to promote bushier growth.
Fertilizing Balanced liquid fertilizer (20-20-20) diluted to half strength, every 4-6 weeks during the growing season (spring and summer).
Seasonal Care Reduce watering in winter as growth slows. Maintain humidity levels year-round. Provide supplemental light if needed during darker months.

🌞 Light Requirements

Oxalis Triangularis

Bright indirect light to partial sun. Requires at least 4-6 hours of bright indirect light daily to maintain vibrant color and prevent legginess.

Low light tolerant: ❌ No

Rex Begonia

Bright, indirect light. Avoid direct sunlight, which can scorch the leaves.

Low light tolerant: ❌ No

💧 Watering Needs

Oxalis Triangularis

Water thoroughly when the top inch of soil feels dry to the touch. Ensure good drainage to prevent root rot. Overwatering can lead to yellowing leaves and stem rot. Underwatering can cause the leaves to droop and become crispy.

Rex Begonia

Water thoroughly when the top inch of soil feels dry to the touch. Avoid overwatering, as this can lead to root rot. Allow excess water to drain away. Reduce watering in winter. Signs of overwatering include yellowing leaves and mushy stems. Underwatering can cause leaves to become crispy and brown.

🌡️ Temperature & Humidity

Oxalis Triangularis

Temperature: 18-24°C

Humidity: 40-60%

Rex Begonia

Temperature: 18-24°C

Humidity: 50-60%

🤔 Which Plant Is Right For You?

Oxalis Triangularis

Oxalis Triangularis

Oxalis triangularis
Care: Easy Time: 5-10 minutes weekly Beginner: Yes

Plant enthusiasts who appreciate unique foliage and enjoy watching plants respond to light.

✅ Choose This Plant If...

  • You love plants with unique foliage and interesting behaviors.
  • You want a relatively low-maintenance plant that adds a pop of color.
  • You enjoy watching plants respond to their environment.
  • You have a bright spot in your home that needs a statement plant.
  • You want a plant that is easy to propagate and share with friends.

❌ Skip This Plant If...

  • You have pets that are prone to eating plants, as it is toxic to them.
  • You struggle to provide adequate bright light for plants.
  • You tend to overwater your plants.
📍 Ideal Location: Bright windowsill, sunroom, or under grow lights.
🎨 Style: Modern, Bohemian, Eclectic
🏠 Apartment Friendly: Yes
⚠️ According to the ASPCA, Oxalis species contain soluble calcium oxalates. These can cause salivation, vomiting, and diarrhea in dogs, cats, and horses. In rare cases, kidney failure can occur.
Rex Begonia

Rex Begonia

Begonia rex
Care: Moderate Time: 10-15 minutes weekly Beginner: With-caution

Experienced plant enthusiasts who appreciate colorful foliage and are willing to provide specific care conditions.

✅ Choose This Plant If...

  • You love plants with unique and colorful foliage.
  • You are willing to provide high humidity and bright, indirect light.
  • You enjoy the challenge of caring for slightly more demanding plants.
  • You want to add a vibrant focal point to your indoor plant collection.
  • You are looking for a plant that can be propagated easily through leaf or rhizome cuttings.

❌ Skip This Plant If...

  • You tend to overwater your plants.
  • You have pets that might ingest the plant.
  • You struggle to maintain high humidity levels in your home.
📍 Ideal Location: Bright bathroom, east-facing windowsill, or near a humidifier.
🎨 Style: Bohemian, Eclectic, Tropical
🏠 Apartment Friendly: Yes
⚠️ Toxic to dogs, cats, and horses. Contains insoluble calcium oxalates. Symptoms include oral irritation, excessive drooling, vomiting, and difficulty swallowing. All parts of the plant are toxic, but the roots are especially concentrated with the oxalates.

🎯 Quick Verdict

Best for Beginners Oxalis Triangularis
Pet Friendly Neither - caution
Less Maintenance Oxalis Triangularis
Apartment Friendly Both work!

⚡ Key Differences Between These Plants

🎯

Oxalis Triangularis is rated Easy care level, while Rex Begonia is Moderate.

💡 Pro Tips For Comparing These Plants

Oxalis Triangularis Care Tips

Oxalis triangularis is relatively easy to care for indoors with proper light and watering. It requires bright indirect light to maintain its vibrant color and prevent legginess. Avoid overwatering and allow the soil to dry slightly between waterings. It can go dormant in the winter, requiring less water.

  • Provide bright, indirect light to maintain vibrant foliage color.
  • Allow the soil to dry slightly between waterings to prevent root rot.
  • Fertilize regularly during the growing season to promote healthy growth.
  • Rotate the plant regularly to ensure even growth on all sides.
  • Consider providing a period of dormancy in the winter by reducing watering and keeping the plant in a cooler location.
❄️ Winter: Reduce watering significantly during the winter months, as the plant may enter a period of dormancy. Keep the plant in a cooler location (around 15-18°C) and provide bright, indirect light. Avoid fertilizing during dormancy.
☀️ Summer: Increase watering during the summer months to keep the soil consistently moist but not waterlogged. Provide bright, indirect light and fertilize regularly to support active growth. Protect the plant from intense direct sunlight, which can scorch the leaves.

Rex Begonia Care Tips

Rex Begonias require bright, indirect light, consistent moisture, and high humidity. They are susceptible to root rot if overwatered. Maintaining adequate humidity can be challenging indoors, often requiring a humidifier or pebble tray. They are not the easiest houseplants but are rewarding for those who can provide the right conditions.

  • Use a well-draining potting mix to prevent root rot.
  • Maintain high humidity by using a humidifier or placing the plant on a pebble tray.
  • Avoid getting water on the leaves, as this can lead to fungal diseases.
  • Rotate the plant regularly to ensure even growth.
  • Fertilize sparingly during the growing season.
❄️ Winter: Reduce watering frequency during the winter months as the plant's growth slows down. Ensure the plant is not exposed to cold drafts. Maintain humidity levels if possible, as indoor heating can dry out the air. Provide supplemental light if needed.
☀️ Summer: Water more frequently during the summer months as the plant actively grows. Protect the plant from direct sunlight to prevent leaf scorch. Increase humidity if necessary. Fertilize regularly during the growing season.

⚠️ Common Problems & Solutions — Plant Care Comparison

Oxalis Triangularis

Common Issues: Leggy growth, Yellowing leaves, Root rot, Pests (spider mites, aphids)
Solutions: Provide more light for leggy growth. Adjust watering and ensure good drainage for yellowing leaves and root rot. Treat pests with insecticidal soap or neem oil.

Rex Begonia

Common Issues: Root rot, Powdery mildew, Mealybugs, Leaf scorch
Solutions: Root rot: Improve drainage and reduce watering frequency. Powdery mildew: Improve air circulation and treat with a fungicide. Mealybugs: Wipe away with a cotton swab dipped in rubbing alcohol or use insecticidal soap. Leaf scorch: Move the plant to a location with less direct sunlight.

❓ Frequently Asked Questions — Comparing These Plants

Oxalis Triangularis

What are the light requirements for Oxalis Triangularis?

Oxalis Triangularis thrives in bright, indirect light. Too much direct sunlight can scorch its delicate leaves, causing them to turn brown or yellow. Insufficient light, on the other hand, can lead to leggy growth and a loss of color intensity. An east-facing window is often ideal, providing gentle morning light. A west-facing window can work if the plant is shielded from the intense afternoon sun.

How do I care for Oxalis Triangularis?

Oxalis Triangularis thrives in bright, indirect light. Avoid direct sunlight, which can scorch the leaves. Water thoroughly when the top inch of soil feels dry, allowing excess water to drain away. Ensure the pot has drainage holes to prevent root rot. Fertilize every 2-4 weeks during the growing season (spring and summer) with a balanced liquid fertilizer diluted to half strength.

How do I propagate Oxalis Triangularis?

Oxalis Triangularis is easily propagated through division. During dormancy, carefully remove the bulbs from the soil. Gently separate the bulbs, ensuring each section has roots. Plant the bulbs in fresh, well-draining potting mix. Water thoroughly and place in bright, indirect light.

Rex Begonia

What are the light requirements for Rex Begonia?

Rex Begonias thrive in bright, indirect light. Direct sunlight can scorch their delicate leaves, causing unsightly burns and hindering growth. An east-facing window is often ideal, providing gentle morning light. West or south-facing windows can work if the plant is positioned further away from the window or shielded by a sheer curtain. Insufficient light will result in dull colors and leggy growth. Rotate the plant regularly to ensure even light exposure on all sides. Artificial light, such as fluorescent or LED grow lights, can supplement natural light, especially during winter months or in dimly lit spaces. The intensity and duration of artificial light should mimic natural daylight patterns.

How do I care for Rex Begonia?

Rex Begonias require bright, indirect light to thrive. Avoid direct sunlight, which can scorch their delicate leaves. Water when the top inch of soil feels dry to the touch, ensuring good drainage to prevent root rot. Maintain high humidity levels, ideally between 60-70%, using a humidifier, pebble tray, or grouping plants together. Fertilize monthly during the growing season (spring and summer) with a balanced, water-soluble fertilizer diluted to half strength, specifically formulated for flowering plants, to encourage blooming. Repot only when necessary, typically every 1-2 years, into a well-draining potting mix. Prune any dead or damaged leaves to maintain the plant’s health and appearance. Keep temperatures consistently between 65-75°F (18-24°C). Be vigilant for pests like mealybugs and spider mites, and treat promptly if detected.

How do I propagate Rex Begonia?

Rex Begonias can be propagated through several methods. Leaf cuttings involve cutting a leaf into wedges, placing them on moist soil, and covering them with a humidity dome. Stem cuttings can be taken from healthy stems and rooted in water or directly in soil. Division involves separating the rhizome into sections, each with roots and leaves, and planting them in individual pots. Keiki paste can be applied to nodes to encourage new plantlets. Regardless of the method, maintain high humidity and provide bright, indirect light. Rooting hormone can improve success rates. Propagation is best done during the spring or summer months. Once roots have developed, gradually acclimate the new plants to regular growing conditions.

Last updated: April 24, 2026 — Plant care data reviewed and verified by our editorial team.