Giant bird-of-paradise flower (Strelitzia nicolai, Regel & Körn. 1858)

Identity

The giant bird-of-paradise flower (Strelitzia nicolai Regel & Körn., 1858), also known as the bird-of-paradise tree, belongs to the genus Strelitzia in the family Strelitziaceae. Regel and Körnicke described it in 1858. Where Strelitzia reginae tops out at 1–2 m (3–6.5 ft) with no trunk, Strelitzia nicolai builds a woody trunk 6–9 m (20–30 ft) tall, and that is the difference you notice first in the field. ^{1 2}

The bird-of-paradise name comes from the flower. A blue-black bract holds white sepals and a purplish blue "tongue," and the whole shape recalls the crested head of an exotic bird, much as in Strelitzia reginae. The name wild banana describes the fan of leaves instead, often mistaken for a young Musa before the trunk appears. ^{3 4}

Recognition

Clumping and tree-like, Strelitzia nicolai raises upright woody stems that form a visible trunk up to 6–9 m (20–30 ft) high, while the whole clump spreads 2–3.5 m (6.5–11.5 ft). Its gray-green leaves, arranged in a fan at the tips of the stems, reach 1.8 m (6 ft) long and shred easily in wind. ^{4 3}

The inflorescence combines a beak-shaped blue-black bract, white sepals and a purplish blue tongue; together they can measure up to 18 cm (7 in) high and 45 cm (18 in) long. Flowers emerge one after another from the same bract and each lasts only a few days, over several weeks of bloom. ^{4 3}

Before its trunk develops, a young plant resembles a banana or a juvenile Strelitzia reginae; only flowering, which takes several years of growth, settles the question with certainty. ³

Useful taxonomy

POWO/WCVP still accepts the name Strelitzia nicolai Regel & Körn. The main synonyms to know are:

• Strelitzia alba subsp. nicolai (Regel & Körn.) Maire & Weiller
• Strelitzia quensonii Lem.

The case of alba subsp. nicolai shows the trap: this demoted rank still turns up in some databases, but it does not replace the accepted name. Nor should the species be confused with Strelitzia alba, a distinct, fully accepted species that shares the loose label of large white-flowered strelitzia. ^{1 5}

Together, Strelitzia nicolai, Strelitzia alba and Strelitzia caudata make up the three large tree-like species of the genus. Because they share the same woody habit, nurseries often mix them up. ⁴

Habitat and range

In the wild, the species ranges from the Great Fish River area in the Eastern Cape to Richards Bay in KwaZulu-Natal, with populations also recorded in Mozambique, Botswana and Zimbabwe. It grows in evergreen coastal forest and coastal thicket across southern Africa. ^{6 3}

Beyond that range, the plant has naturalized in the Mexican state of Veracruz and in eastern Australia, between northern New South Wales and southern Queensland. It is also grown in Florida, coastal California and around the Mediterranean: once rooted, it copes with poor soil and salty sea air. ^{4 3}

Life cycle and reproduction

Where it is cultivated, bloom begins in spring; in its native southern African range, it runs from June to September. Whether raised from seed or a division, a young plant needs 5–10 years to form a trunk before its first flower. ^{6 3}

Sunbirds and other nectar-feeding birds pollinate the flower in the wild by perching on the bract. Monkeys also feed on the flowers and seeds, and frogs and ducks shelter in the dense foliage. After pollination, the flower gives way to a brown, three-sided capsule that releases black seeds capped with an orange aril. ³

For gardeners, offshoot division of basal suckers yields a flowering plant sooner than seed, which needs soaking first and several patient years before the first bloom. ^{4 3}

Uses and risks

Ornamental, architectural planting remains the main use: in mild climates, roughly USDA zones 10 and 11, the fan-shaped silhouette anchors a sunny bed, a patio or a poolside. Where winters bring frost, it stays a large specimen for an atrium or a very bright room indoors. Locally, its dried stems are also twisted into rope. ³

Contact with the sap irritates the skin. Eating the fruit, seeds or leaves causes nausea, vomiting and drowsiness in cats, dogs and horses, and may bring abdominal cramps and diarrhea in people. ³

Chemical analysis has confirmed that Strelitzia nicolai is one of the rare plants containing bilirubin, a pigment usually associated with the breakdown of hemoglobin in animals. ^{7 4}

Varieties, look-alikes and related plants

No widely distributed, stable cultivar exists for this species; the differences seen at nurseries mostly concern vigor and how quickly a trunk forms in a given growing climate. ³

Common look-alikes include:

• Strelitzia alba, another large tree-like strelitzia with white flowers, distinct but often sold under the same trade name
• Strelitzia caudata, the third large tree-like species of the genus, with more restricted populations
• Ravenala madagascariensis, whose fan of leaves is almost identical, although the two genera belong to separate families
• young bananas of the genus Musa, whose juvenile foliage resembles a Strelitzia nicolai that has not yet formed a trunk
• Strelitzia reginae, much smaller, herbaceous and trunkless, with orange and blue flowers

Without a flower or a well-formed trunk, these plants are hard to tell apart with certainty from foliage alone.

Main sources

• Plants of the World Online / Kew, Strelitzia nicolai Regel & Körn.
• International Plant Names Index, Strelitzia nicolai Regel & Körn.
• GBIF Backbone Taxonomy, Strelitzia nicolai
• NC State Extension Gardener Plant Toolbox, Strelitzia nicolai
• Wikipedia (en), Strelitzia nicolai
• Wikipedia (fr), Strelitzia nicolai
• INPN / MNHN, Strelitzia nicolai, oiseau du paradis blanc
• PubMed / NCBI, bilirubin pigment identified in Strelitzia nicolai (PMID 19206232)