Houstonia rubra
Houstonia rubra
Houstonia rubra, the red bluet, is a plant species in the Rubiaceae. It is a small herb with white to pink to red to reddish-purple flowers, native to the southwestern United States and northern and central Mexico: Coahuila, Nuevo León, Hidalgo, Zacatecas, Guanajuato, Puebla, Sonora, Durango, Chihuahua, Arizona, New Mexico, southeastern Utah and western Texas.
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Gallery
Houstonia rubra - Flickr - aspidoscelisRed-bluet SF River
Houstonia rubra - Flickr - aspidoscelis (1)
Houstonia rubra - Flickr - aspidoscelis (2)Houstonia rubra - Flickr - aspidoscelisRed-bluet SF RiverOverview
Houstonia rubra is a plant species in the family Rubiaceae. GBIF holds 866 occurrence records across 2 countries. Its records concentrate in United States, Mexico.
Life cycle
From seed to productSeed & germination
The plant is propagated mainly by **seed**: sow fresh or pre-treated seed in loose, moist soil and keep it evenly damp; germination follows within a few weeks.
Seedling & growth
Seedlings establish, forming leaves and roots; growth rate depends on light and moisture.
Flowering
The plant blooms with **pale purple tubular flowers, spring–summer**; pollination is by insects and wind.
Fruiting & harvest
The plant matures and blooms profusely in season; **ripe capsules gathered summer–autumn**.
Distribution & origin
Share of recorded occurrences by region- United States64%
- Mexico36%
References
- 1Houstonia rubra — Wikipedia — Wikipedia (CC BY-SA 4.0), 2026
- 2World Checklist of Selected Plant Families: Royal Botanic Gardens, Kew — Wikipedia,
- 3County Houstonia map — Wikipedia,
- 4GBIF — occurrence records of Houstonia rubra — GBIF, 2026
- 5Hình ảnh — Wikimedia Commons (4 ảnh, giấy phép CC/PD) — Wikimedia Commons, 2026