Lorenzia umbrosa E.G.Gonç.

• Genus: Lorenzia
• Botanical Background: Described by Eduardo G. Gonçalves (2012) based on cultivated material that flowered after DNA evidence suggested its novelty. The genus honors Brazilian botanist Harri Lorenzi.

• Geographical Range: Endemic to a single locality in Serra do Navio, Amapá, Brazil; possibly adjacent French Guiana.
• Environment: Understorey of lowland Amazon rainforest; constant high humidity (>80%), stable warm temperatures (22–28 °C), acidic, well‑draining organic soil.

Leaves

• Sagittate‑shaped, 5–11 × 2.5–8 cm, glossy green above, lighter beneath
• Reticulate venation
• Densely pilose

Inflorescence (Spadix & Spathe)

• SSingle to paired
• Spathe elliptic (3–5.5 × 1–2 cm), purple‑brown
• Spadix ~2 cm, lightly scented
• Likely pollinated by small beetles

Growth Habit

• Terrestrial rhizomatous geophyte with underground stems
• Produces solitary foliage leaves spaced by cataphylls

Light Requirements

• Bright, indirect light
• Avoid direct sun

Watering & Humidity

• Keep soil evenly moist but not waterlogged
• Maintain >70% humidity

Soil & Potting Mix

• Use loose, well‑draining mix (peat, orchid bark, perlite)
• Terracotta or plastic pot with drainage

Temperature & Fertilizer

• Ideal 20–28 °C
• Feed monthly (balanced liquid fertilizer at half strength) during active growth

Division

• Best via rhizome division when repotting
• Ensure each division has ≥1 leaf node

Seeds

• No documented cultivation from seed

• Viability likely low outside native habitat

Typical Issues

• Susceptible to root rot if overwatered
• Occasional mealybugs or spider mites in low‑airflow conditions

Treatment Recommendations

• Improve drainage
• Use neem oil or insecticidal soap for pests
• Fungicide drench (e.g., copper-based) for root rot

• Late flowering in cultivation (2010) confirmed its distinct genus status
• Named for Harri Lorenzi’s contributions

• Valued by collectors for rarity and compact form
• Seldom available commercially

Wild Population Status

• Known only from one locality

• Not yet IUCN‑assessed but likely Vulnerable

Market Availability

• Extremely rare
• Limited to specialized botanical gardens and aroid collectors