North America Native Plant

Small’s Rainlily

Botanical name: Cooperia smallii

USDA symbol: COSM

Life cycle: perennial

Habit: forb

Native status: Native to the lower 48 states  

Synonyms: Zephyranthes smallii (Alexander) Traub (ZESM2)   

Small’s Rainlily: A Rare Texas Treasure Worth Protecting If you’re a Texas native plant enthusiast looking for something truly special, Small’s rainlily (Cooperia smallii) might just capture your heart. This little-known bulb is one of Texas’s botanical gems – and one that deserves our careful attention and protection. What Makes ...

Rare plant alert!

Region: Conservation status by state

Status: S1S2Q: Status is uncertain but is somewhere between the following rankings: Uncertain taxonomy: ⚘ Critically Imperiled: Extremely rare due to factor(s) making it especially vulnerable to extinction. Typically 5 or fewer occurrences or very few remaining individuals (<1,000) ⚘ Imperiled: Extremely rare due to factor(s) making it especially vulnerable to extinction. Typically 6 to 20 occurrences or few remaining individuals (1,000 to 3,000) ⚘

Small’s Rainlily: A Rare Texas Treasure Worth Protecting

If you’re a Texas native plant enthusiast looking for something truly special, Small’s rainlily (Cooperia smallii) might just capture your heart. This little-known bulb is one of Texas’s botanical gems – and one that deserves our careful attention and protection.

What Makes Small’s Rainlily Special?

Small’s rainlily is a perennial forb that belongs to the fascinating world of rain-triggered bloomers. Like other members of its family, this charming bulb has earned its common name from its delightful habit of producing flowers shortly after rainfall. The plant develops grass-like foliage and produces small, white, funnel-shaped flowers that seem to appear almost magically after a good soaking.

You might also encounter this plant listed under its synonym, Zephyranthes smallii, in older gardening references or plant catalogs.

A True Texas Native – But Rare

Small’s rainlily is endemic to Texas, meaning it grows naturally nowhere else in the world. However, here’s where things get serious: this plant has a Global Conservation Status of S1S2Q, indicating it’s critically imperiled to imperiled in the wild.

Important Conservation Note: Due to its rarity status, if you’re interested in growing Small’s rainlily, please only purchase from reputable native plant nurseries that propagate their own stock or work with conservation programs. Never collect this plant from the wild, and always verify that any plants you purchase are responsibly sourced.

Should You Grow Small’s Rainlily?

For the right gardener, Small’s rainlily can be a meaningful addition to a native Texas landscape. Here’s what to consider:

The Case for Growing It:

  • You’ll be supporting conservation efforts for a rare Texas endemic
  • It’s perfectly adapted to Texas growing conditions
  • The surprise blooms after rain events add an element of natural wonder to your garden
  • It requires minimal care once established
  • Attracts nocturnal pollinators like moths

Consider Your Commitment:

  • This plant requires a dedicated commitment to conservation-minded gardening
  • It may be difficult to source from nurseries
  • Its specialized nature means it’s not for casual gardeners

Growing Conditions and Care

If you’ve decided to take on the responsibility of growing this rare beauty, here’s what Small’s rainlily needs to thrive:

Ideal Growing Conditions:

  • Sunlight: Full sun to partial shade
  • Soil: Well-draining soil is essential
  • Water: Drought tolerant once established; enjoys natural rainfall cycles
  • Climate: USDA Hardiness Zones 8-10 (Texas climate)

Planting and Care Tips:

  • Plant bulbs in fall when temperatures begin to cool
  • Choose a location with good drainage to prevent bulb rot
  • Once established, minimal intervention is needed
  • Allow natural rainfall cycles to trigger blooming
  • Avoid overwatering, especially during dormant periods

The Perfect Garden Setting

Small’s rainlily works best in specialized native Texas gardens, rock gardens, or naturalized areas where its subtle beauty can be appreciated. It’s ideal for gardeners who enjoy observing the intricate relationships between plants and their environment, particularly the fascinating connection between rainfall and blooming cycles.

A Plant Worth Protecting

Growing Small’s rainlily isn’t just about adding another plant to your garden – it’s about participating in conservation efforts for Texas’s unique botanical heritage. By choosing to grow this rare species responsibly, you’re helping ensure that future generations will have the opportunity to experience this remarkable little rain lily.

If you’re not ready for the commitment that comes with growing a rare species, consider other Texas native bulbs and rain lilies that can provide similar garden interest while supporting local ecosystems. Your local native plant society can help you identify good alternatives that match your gardening goals and conservation comfort level.

Small’s Rainlily

Classification

Group

Monocot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Liliopsida - Monocotyledons

Subclass

Liliidae

Order

Liliales

Family

Liliaceae Juss. - Lily family

Genus

Cooperia Herb. - rainlily

Species

Cooperia smallii Alexander - Small's rainlily

Plant data source: USDA, NRCS 2025. The PLANTS Database. https://plants.usda.gov,. 2/25/2025. National Plant Data Team, Greensboro, NC USA