Beach Morning Glory
Botanical name: Ipomoea pes-caprae subsp. brasiliensis
Synonyms: None
Common name(s): Beach Morning Glory
About:
A remarkable tropical and subtropical coastal vine that reaches the southern limit of its natural global range in northern New Zealand. Ipomoea pes-caprae subsp. brasiliensis is a stout, perennial, ground-hugging scrambler with long creeping stems, thick glossy leaves and conspicuous pink, rose-purple or lavender funnel-shaped flowers.
It is exceptionally well adapted to life immediately above the high-tide line. Its stems can trail for many metres across exposed sand, rooting at the nodes to form extensive mats. The thick leaves tolerate intense sun, salt spray and drying winds, while its buoyant seeds can survive transport by seawater.
Natural habitat:
Almost exclusively coastal and typically a true beach-strand plant.
It grows immediately above the high-tide mark, amongst driftwood and debris, and around the bases and seaward faces of foredunes.
Throughout its wider range it occurs on tropical and subtropical beaches, coastal sand, gravel beaches and occasionally coastal cliffs.
On the Kermadec Islands it has unusually also been recorded around the margins of active fumaroles.
Growing environment:
Full Sun, Salt Spray, Strong Wind, Heat, Sand & Coastal Exposure tolerant.
Requires a warm to subtropical climate and is extremely frost and cold sensitive. It performs best on freely draining sandy substrates in open coastal situations.
Despite its tolerance of extreme coastal exposure, it can be surprisingly difficult to cultivate in cooler New Zealand conditions.
Endemic distribution:
Indigenous but not endemic to New Zealand.
In New Zealand it is common on some of the Kermadec Islands.
On the mainland it is extremely restricted, with an extant natural population in the Te Paki area of far northern Northland. A former population near Waipapakauri at the southern end of Te Oneroa-a-Tōhē / Ninety Mile Beach was destroyed.
New Zealand represents the southern extreme of the species’ natural global distribution.
Internationally it is widespread around tropical and subtropical shores of the Pacific and other warm regions of the world.
Height:
Usually only around 10–30 cm above the ground.
The plant spreads horizontally rather than growing upright.
Width:
Individual trailing stems can reach approximately 20 m long.
By rooting freely at the nodes, a single established plant can eventually form a very extensive mat.
Flowering:
October–April.
Individual flowers are relatively short-lived, typically opening during the morning.
Fruiting:
October–August.
Rounded capsules develop after flowering and contain large brown, hairy seeds.
Uses:
• Coastal dune stabilisation
• Sand binding
• Beach-strand restoration within its natural range
• Coastal erosion control
• Specialist native plant collections
• Ecological and botanical collections
• Tropical coastal landscaping in suitable climates
Because mainland New Zealand populations are extremely restricted, ecological restoration should use appropriately sourced local material.
Appearance:
Growth habit:
A stout, tap-rooted, perennial scrambling vine with numerous prostrate stems.
Stems may trail for up to approximately 20 m and root readily where their nodes contact suitable substrate, allowing the plant to produce large mats across open beach sand.
The stems contain milky latex.
Leaves:
Leaves are large, thick, fleshy and usually glossy dark to bright green.
They are approximately 4–12 cm long, occasionally reaching around 17 cm, and approximately 3.5–12 cm wide.
The blade varies from broad-oblong to almost circular and has an entire, smooth margin.
The apex is characteristically notched or shallowly divided into two rounded lobes, producing the distinctive shape responsible for the species name pes-caprae, meaning “goat’s foot”.
Leaves are borne on stout, fleshy petioles that may exceed 11 cm long.
Flowers:
Flowers are large and funnel-shaped, usually approximately 3–5 cm long and 4–5.5 cm across.
Colour ranges from bright pink and rose-pink to lavender or violet, with an irregular darker rose-coloured band around the inner base of the expanded corolla. White-flowered plants occur rarely elsewhere within its range.
Flowers are produced singly or in small clusters from the leaf axils.
Fruit:
Fruit is a globose to ovoid dry capsule approximately 1.2–2 cm across.
Each capsule usually contains 2–4 relatively large, dark brown seeds covered in short hairs.
The seeds are buoyant and highly adapted to oceanic dispersal, allowing them to travel considerable distances in seawater before being deposited on suitable beaches.
Ecology:
Ipomoea pes-caprae subsp. brasiliensis is one of the world’s characteristic tropical beach-strand plants.
Its long, rapidly spreading stems trap windblown sand and root at multiple nodes, helping stabilise the highly mobile substrate immediately above the high-tide line. This growth can produce dense mats capable of surviving conditions that exclude most terrestrial plants.
The thick leaves and robust stems withstand strong sunlight, high temperatures, salt spray and persistent coastal winds.
Its flowers provide nectar and pollen to insects, particularly bees, while butterflies, moths, beetles and other insects may also visit them.
Water is particularly important for long-distance dispersal. The buoyant seeds can be carried by ocean currents between islands and coastlines, helping explain the species’ extraordinarily broad tropical distribution.
Associated habitats:
Beach strand, foredunes, coastal sand dunes, driftwood zones, sandy beaches, gravel beaches, coastal cliffs, open coastal vegetation and, unusually on the Kermadec Islands, geothermal fumarole margins.
How to grow:
A specialised plant requiring warm coastal conditions.
Grow in full sun in very freely draining sandy soil. Warmth is essential, and the plant should be protected from frost and prolonged cold.
It tolerates salt spray, wind, intense sunlight and nutrient-poor beach sand exceptionally well once established.
In New Zealand, however, cultivation becomes increasingly difficult south of the warmest northern districts. Even the relatively mild climate of northern Northland can present challenges.
It should therefore be regarded primarily as a specialist coastal or conservation plant rather than a general-purpose garden groundcover.
Propagation:
Easily propagated from fresh seed under sufficiently warm conditions.
The hard seed coat benefits from scarification before sowing. Seeds can then be soaked until swollen and planted into a warm, freely draining sandy medium.
It can also be propagated from stem sections containing viable nodes, which are capable of producing new roots under warm, humid conditions.
Young plants must be protected from cold temperatures.
Cultural use:
No specific traditional Māori use is well documented for the extremely restricted New Zealand populations.
The botanical name reflects the plant’s distinctive appearance. Ipomoea derives from Greek roots referring to the twining or worm-like growth of members of the genus, while pes-caprae means “goat’s foot”, referring to the characteristic two-lobed leaves. Brasiliensis refers to Brazil.
The species has a long history of medicinal use among peoples elsewhere in its extensive tropical range, although these overseas uses should not be interpreted as documented Māori uses in Aotearoa.
Garden value:
A spectacular and highly specialised coastal native at the extreme southern edge of its natural range.
Its glossy, fleshy goat’s-foot-shaped leaves, enormous creeping habit and vivid pink morning-glory flowers give it a distinctly tropical appearance unlike almost any other naturally occurring mainland New Zealand plant.
Its greatest value in New Zealand lies in conservation, specialist collections and ecological restoration in the far north and Kermadec Islands. Where climate and provenance are appropriate, it is also an exceptional sand-binding species capable of creating attractive flowering mats across exposed beach environments.