Mazus radicans (Hook.fil.) Cheeseman

Taxonomic Identity

Mazus radicans (Hook.fil.) Cheeseman is a small, creeping wetland herb native to New Zealand.

Main Branch Morphology

Its main branches grow prostrate and root at their nodes. Lateral branches are short and leafy, with distinctive internodes on leaf-bearing, horizontal, or subterranean branches.

Leaf Color

Its leaves are brownish in color.

Leaf Petiole Structure

The leaf petiole is 3–70 mm (0.12–2.76 in) long, with a membranous wing along each side.

Leaf Blade Dimensions

Leaf blades are obovate, elliptic, or broader, measuring roughly 5–35 mm (0.20–1.38 in) long by 4–15 mm (0.16–0.59 in) wide.

Leaf Blade Morphology

Leaf bases narrow gradually, blade margins are slightly undulate to serrate, and leaf apices are broadly acute to rounded. Soft hairs cover the leaf margins.

Inflorescence Position

Inflorescences typically grow at the tips of short lateral branches, with floral structures 15–130 mm (0.59–5.12 in) long.

Pedicel Bract Characteristics

Most pedicels lack bracts, and any existing bracts fall off early. Alternating bracteoles of uniform size and shape grow along 3–35 mm (0.12–1.38 in) long pedicels.

Lower Bracteole Morphology

Lower bracteoles occasionally bud, measure 2.5–7 mm (0.098–0.276 in) long, and have sparse soft hairs.

Calyx and Flower Color

The calyx is roughly 3–7.5 mm (0.12–0.30 in) long, and bears purple flowers. The exterior of the flower is white with purple outer tissue, while the inner tissue is deep purple. The flower lip is white and yellow.

Lower Lip Structure

The lower lip has rounded lobes that are glabrous except for the flower palate.

Flower Tube and Upper Lip

The flower tube is twice as long as the calyx. The upper lip is 4–8.5 mm (0.16–0.33 in) long, and the plant produces persistent capsule fruits that do not detach from the plant.

Fruit Characteristics

The fruit is pinkish-red in color and broadly ellipsoid in shape.

South Island Distribution

In New Zealand, this species is a common wetland weed on the South Island, where it occurs in damp environments including natural wetlands and swamps.

North Island Distribution

As an endemic species on the North Island, it is found at Awanui near Kaitaia, Hautai Beach, and Waipapa Stream near East Cape.

Elevation Range

It grows at elevations from 100 to 1100 m above sea level across most of New Zealand, and extends into alpine regions up to 1,200 m (3,900 ft) from Mt Egmont/Taranaki and the Huiarau Ranges southward to Fiordland.

General Habitat Types

Its preferred habitats include lowland swamp forest, sparsely vegetated coastal wetlands, and moist subalpine areas.

Site Preference

It favors sites with short, dense sedges and grasses, and often grows in areas that are seasonally flooded or heavily grazed.

Growth Cycle Type

Mazus radicans can be either a perennial or annual herb.

Flowering Period

In New Zealand, it typically flowers from November to March, which is the local summer.

Fruit Development

Fruits mature in autumn and remain attached to the plant.

Seed Germination

Fresh seeds germinate easily.

Reproductive Habitat Requirements

The best environment for its reproduction is permanently moist, poorly drained soil in shaded, sheltered ground.

Pollination

Bees pollinate its flowers.