Leucospermum pluridens Rourke

Scientific Naming and Growth Form

Leucospermum pluridens, scientifically named Leucospermum pluridens Rourke, is an upright, rigid, evergreen tree-like shrub that can reach up to 3 m (9.8 ft) in diameter.

Trunk and Bark Characteristics

It grows from a woody trunk of up to 20 cm (7.9 in) in diameter, which along with lower branches is covered in smooth grey bark.

Branching Pattern

Characteristically, young plants branch only sparsely from their stiff upright stems, while older plants develop more branches.

Flowering Branch Traits

Flowering branches are stout and woody, measuring 3⁄4–1 cm (0.3–0.4 in) across, with a thick grey felty or spiderweb-like covering made of short crinkled hairs.

Leaf Shape and Texture

Leaves are arranged alternately, slightly overlapping, hairless and leathery, and shaped oblong, broadly inverted lance-shaped, or wedge-shaped.

Leaf Dimensions

They are 5+1⁄2–10 cm (2.2–3.9 in) long and 2–3+1⁄2 cm (0.79–1.38 in) wide.

Leaf Tip Features

The leaf tip is rounded, often deeply incised, and bears seven to ten very prominent rounded teeth.

Flowerhead Shape and Size

Flowerheads are egg-shaped, about 8 cm (3+1⁄4 in) high and 6 cm (2.4 in) across.

Flowerhead Arrangement

They are either seated or have a very short stalk, most often growing individually but sometimes occurring in groups of up to four on a single flowering branch.

Flowerhead Common Base

The common base of the flowers within one head is narrowly cone-shaped with a pointed tip, 3+1⁄2–4 cm (1.4–1.6 in) long and about 1 cm (0.39 in) wide.

Head-Subtending Bract Shape

Bracts subtending the entire head are oval, keeled, with a very long narrowing, hook-shaped tip up to 2 cm (0.79 in) long.

Head-Subtending Bract Surface Features

They have a row of long hairs along their edges, and their inner surface is shiny and carmine-coloured in living specimens.

Individual Flower Bract Traits

The bract subtending each individual flower is cartilaginous, keeled, and wraps around the flower base, about 1 cm long and 6 mm wide.

Individual Flower Bract Tip and Edges

It has a long pointed tip that curves slightly inward, with a row of long hairs along the edges.

Perianth Merosity

The perianth is 4-merous.

Perianth Tube Characteristics

The lower merged portion of the perianth, called the tube, is about 10 mm (0.39 in) long, cylinder-shaped, somewhat sideways compressed, hairless at its base and slightly powdery higher up.

Perianth Claw Color and Hairs

The middle portions, or claws, are initially yellow, turning bright carmine, with rough hairs on the inner surface that mix long straight hairs with short felty hairs.

Central Perianth Claw Feature

The claw facing the center of the flowerhead is hairless near its base.

Perianth Limb Shape and Texture

The upper portions, or limbs, which enclose the pollen presenter within the bud, are broadly lance-shaped with a pointed tip, each about 5 mm long and 2 mm wide, and covered in felt.

Perianth Limb Hair Variation

Limbs facing the head center and sides also have additional long silky hairs, while the limb facing the edge of the head is less densely felty than the other three.

Style Characteristics

A slender tapering style emerges from the center of the perianth, 5–6 cm (2.0–2.4 in) long and about 1½ mm thick, with its upper portion slightly curved toward the center of the head.

Pollen Presenter Color and Shape

The thickened tip of the style, called the pollen presenter, is orange on its lower half and yellow on its upper half, cone-shaped with a pointed tip.

Pollen Presenter Dimensions and Stigma

It is about 2 mm (0.079 in) long and 1 mm wide, with a green stigma groove running across its very tip.

Ovary Scales

The ovary is subtended by four white, awl-shaped scales about 2 mm (0.079 in) long.

Common Name

The common name of this species is Robinson pincushion.

Species Distribution

It grows on the lower northern slopes of the Outeniqua Mountains near "Klein Moeras Rivier Spruiten", Saffraan Rivier and Kruis Pad, at an altitude of 500–600 m (1,600–2,000 ft), and on the southeastern slopes of the Rooiberg at an altitude of 750–1,050 m (2,460–3,440 ft). It also grows in the Baviaanskloof.

Habitat Vegetation Type

At both of its main locations, the species occurs in Arid Fynbos, a transitional vegetation type at the interface between fynbos and Karoo.

Associated Vegetation

This is most evident at Kruis Pad, where this species grows alongside Aloe ferox, several species of Cotyledon, Elytropappus, and Restionaceae on dry, hot, north-facing hills.

Precipitation Requirements

Within its distribution, average annual precipitation is 250–400 mm (10–15 in), which makes its moisture requirements quite different from those of its close relative L. glabrum.

Fruit Ripening Timing

Fruits ripen about two months after flowering, then fall to the ground.

Seed Dispersal and Germination

Ants gather the fallen fruits and carry them to their underground nests, where the seeds remain until they germinate after a fire removes the overhead vegetation cover.