Arum vs Oxalis Triangularis Plant Comparison
Compare these two plants side by side — care needs, key differences, and which is right for your home.
Arum
Arum italicum
Arum italicum is a tuberous herbaceous perennial known for its striking foliage and distinctive spadix and spathe flower structure. It emerges in the fall with arrow-shaped leaves, often beautifully veined in white or cream. The plant goes dormant in the summer. It is primarily an outdoor plant, thriving in woodland conditions. While it can be grown indoors, it requires very specific conditions to mimic its natural habitat. People grow it for its attractive foliage and unique flower structure.
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.
Quick Plant Comparison
| Feature | Arum | Oxalis Triangularis |
|---|---|---|
| Light | Partial to full shade outdoors. Indoors, requires very bright, indirect light, ideally a north-facing window or under grow lights. | Bright indirect light to partial sun. Requires at least 4-6 hours of bright indirect light daily to maintain vibrant color and prevent legginess. |
| Watering | Every 10-14 days during growing season, much less frequently during dormancy. | Every 7-10 days, depending on environmental conditions |
| Humidity | 40-60% | 40-60% |
| Temperature | 10-21°C | 18-24°C |
| Care Level | Expert | Easy |
| Growth Rate | Moderate | Moderate |
| Max Height | Indoors: 30-60 cm | 30-45 cm |
| Pet Safety | ❌ Toxic To Pets | ❌ Toxic To Pets |
| Soil | Well-draining, humus-rich soil. A mix of potting soil, peat moss, and perlite is suitable. | Well-draining potting mix, such as a mix of peat moss, perlite, and vermiculite. |
| Beginner Friendly | ❌ No | ✅ Yes |
| Weekly Maintenance | 15 minutes weekly during growing season, 5 minutes during dormancy. | 5-10 minutes weekly |
🔬 Botanical Information — Comparing These Plants
Arum
| Scientific Name | Arum italicum |
|---|---|
| Family | Araceae |
| Native To | Mediterranean region, from Portugal and Morocco to Turkey and Crimea |
| Also Known As | Italian Arum, Italian Lords-and-Ladies, Painted Arum |
| Leaves | The leaves are arrow-shaped, typically 20-30 cm long, and often feature prominent white or cream-colored veins. The texture is smooth and slightly waxy. |
| Flowers | Arum italicum produces a spadix and spathe flower structure. The spathe is a creamy-white or greenish-white hood-like structure that surrounds the spadix, a fleshy spike covered in tiny flowers. It rarely flowers indoors. |
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. |
📏 Size & Growth — Plant Comparison
Arum
Oxalis Triangularis
🌱 Propagation — Comparing Plant Growth
Arum
Methods: Division of tubers, Seed
Difficulty: Moderate
Tips: Divide tubers in late summer or early fall. Sow seeds in the fall after the berries have ripened. Ensure good drainage when planting.
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.
✨ Benefits & Features — Comparing Plant Value
Arum
Arum italicum is unique for its winter foliage, which appears after most plants have lost their leaves. Its distinctive spadix and spathe flower structure also set it apart from other plants.
- ✓ Unique and striking appearance.
- ✓ Adds visual interest to shady areas.
- ✓ Can be a conversation starter.
- ✓ Provides a touch of the Mediterranean landscape.
- ✓ Offers a seasonal display of foliage and berries.
- ⚠️ Toxic to pets
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
📅 Maintenance Schedule — Plant Care Comparison
Arum
Oxalis Triangularis
🌞 Light Requirements
Arum
Partial to full shade outdoors. Indoors, requires very bright, indirect light, ideally a north-facing window or under grow lights.
Low light tolerant: ❌ No
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
💧 Watering Needs
Arum
Water thoroughly when the top inch of soil is dry during the growing season (fall to spring). Reduce watering significantly during dormancy (summer). Overwatering can lead to tuber rot. Underwatering will cause the leaves to wilt and brown.
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.
🌡️ Temperature & Humidity
Arum
Temperature: 10-21°C
Humidity: 40-60%
Oxalis Triangularis
Temperature: 18-24°C
Humidity: 40-60%
🤔 Which Plant Is Right For You?
Arum
Arum italicumExperienced gardeners who want a unique plant and can provide the specific conditions it needs.
✅ Choose This Plant If...
- You appreciate unique foliage and a striking plant structure.
- You can provide a cool, dormant period in the summer.
- You are an experienced gardener comfortable with challenging plants.
- You have a shady spot in your garden or can mimic those conditions indoors.
- You are prepared to handle a toxic plant and keep it away from pets and children.
❌ Skip This Plant If...
- You have pets or small children who might ingest the plant.
- You are a beginner gardener.
- You cannot provide a cool, dormant period.
- You don't have a bright, indirect light source.
- You prefer low-maintenance plants.
Oxalis Triangularis
Oxalis triangularisPlant 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.
🎯 Quick Verdict
⚡ Key Differences Between These Plants
Arum is rated Expert care level, while Oxalis Triangularis is Easy.
💡 Pro Tips For Comparing These Plants
Arum Care Tips
Arum italicum is primarily an outdoor plant and requires expert care to thrive indoors. It needs specific light, temperature, and dormancy conditions. It is toxic to pets. Indoor cultivation is challenging due to its seasonal growth cycle and need for a cool, dormant period.
- Provide a cool, dry dormant period in the summer by reducing watering significantly and keeping the plant in a cooler location.
- Ensure excellent drainage to prevent tuber rot.
- Fertilize regularly during the growing season with a balanced liquid fertilizer.
- Monitor for pests like aphids and spider mites and treat promptly.
- Wear gloves when handling the plant to avoid skin irritation from the sap.
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.
⚠️ Common Problems & Solutions — Plant Care Comparison
Arum
Oxalis Triangularis
❓ Frequently Asked Questions — Comparing These Plants
Arum
What are the light requirements for Arum?
Arum plants thrive best in bright, indirect light. Direct sunlight can scorch the leaves, so avoid placing them in areas with intense midday sun. An east-facing window is often ideal, providing gentle morning light. If you only have south or west-facing windows, filter the light with sheer curtains or blinds. Insufficient light can result in leggy growth and reduced flowering. Rotate the plant regularly to ensure even light exposure on all sides. During the darker months, consider supplementing with artificial grow lights to maintain healthy growth. Observe the plant’s foliage; if the leaves appear pale or stretched, it’s a sign that it needs more light.
How do I care for Arum?
Arum plants prefer bright, indirect light but can tolerate some shade. Water thoroughly when the top inch of soil feels dry to the touch, ensuring good drainage to prevent root rot. Fertilize monthly during the growing season (spring and summer) with a balanced liquid fertilizer diluted to half strength. Reduce watering and fertilization during the dormant period in fall and winter. Maintain moderate humidity, especially indoors. Repot every 1-2 years in spring, using a well-draining potting mix. Prune away any yellowing or dead leaves to encourage healthy growth. Protect from frost as Arum is not cold hardy. Monitor for pests such as aphids or spider mites and treat accordingly. Proper air circulation is essential to prevent fungal diseases.
How do I propagate Arum?
Arum can be propagated through division, stem cuttings, or from bulb offsets (keikis).
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.
Last updated: April 19, 2026 — Plant care data reviewed and verified by our editorial team.