Angraecum eburneum subsp. giryamae

Names and Taxonomy

The accepted name for this taxon is Angraecum eburneum subsp. giryamae (Rendle) Senghas & P.J.Cribb. Kew’s Plants of the World Online lists it as an accepted subspecies and records the original publication in Orchidee 30(1): cxxi (1979)【1】. The basionym is Angraecum giryamae Rendle, published in 1895【1】. No other competing names are currently accepted.

How to Identify This Species

Field and cultivated specimens share the following diagnostic features:

• Growth form: Lithophytic subshrub, stems up to 1 m (3 ft) long, often forming large clumps.
• Roots: Thick, fleshy, about 5 mm in diameter.
• Leaves: Numerous, distichous, strap‑shaped, up to 50 cm × 7 cm (20 in × 3 in), bilobed at the apex.
• Inflorescence: Erect, 30–75 cm (12–30 in) long, bearing 8–20 flowers.
• Flowers: Non‑resupinate, night‑scented; sepals and petals greenish‑white, 32–45 mm × 5–7 mm, linear‑lanceolate; lip white, 20–30 mm × 30–40 mm, with a 5 mm apicule; spur 4–6 cm (2 in) long.
• Fragrance: Strong nocturnal scent, reported as gardenia‑like.

These characters, especially the long spur and night fragrance, help separate it from the other Angraecum eburneum subspecies, which differ in lip proportions and spur length.

Native Range and Habitat

The subspecies occurs in southeastern Kenya through eastern Tanzania, including the islands of Pemba and Zanzibar. Kew records the native range as “SE. Kenya to E. Tanzania (incl. Pemba, Zanzibar)”【1】. It grows primarily as a lithophyte on coral rock near the sea but can be epiphytic inland. Habitat is described as seasonally dry tropical, usually below 350 m elevation but with records up to 1 700 m【5】. The species prefers well‑drained, rocky substrates and tolerates the coastal microclimate of the Indian Ocean.

Species‑Specific Care

Scroll to explore the table →

Because the plant is lithophytic in the wild, excellent airflow and a gritty medium are critical to prevent root rot. When grown in a greenhouse, provide bright, indirect light and maintain night temperatures above 15 °C.

Flowering and Pollination

Flowering occurs in the early winter months in the Southern Hemisphere and can extend into late winter in cultivated settings. Flowers are long‑lived, lasting several weeks, and emit a strong nocturnal fragrance that attracts moth pollinators. The 4–6 cm nectar spur is typical of moth‑pollinated Angraecum species, although specific pollinator observations for this subspecies are not recorded in the available sources.

Common Growing Problems

Not documented in the available sources. Growers should monitor for typical lithophytic orchid issues such as root rot from excessive moisture and pests common to coastal orchids.

Evidence and Limitations

The profile relies on Kew’s taxonomic database, the African Orchids cultivation description, and a Smithsonian Gardens specimen record. Detailed temperature ranges, humidity targets, and pest management are derived from general lithophytic guidance rather than species‑specific trials. Further field studies would be valuable for confirming pollinator identity, exact elevation limits, and conservation status.