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Telopea truncata

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Telopea truncata

Telopea truncata, commonly known as the Tasmanian waratah, is a plant in the family Proteaceae. It is endemic to Tasmania where it is found on moist acidic soils at altitudes of 600 to 1200 m (2000–4000 ft). Telopea truncata is a component of alpine eucalypt forest, rainforest and scrub communities. It grows as a multistemmed shrub to a height of 3 metres (10 ft), or occasionally as a small tree to 10 m (35 ft) high, with red flower heads, known as inflorescences, appearing over the Tasmanian summer (November to February) and bearing 10 to 35 individual flowers. Yellow-flowered forms are occasionally seen, but do not form a population distinct from the rest of the species.

Collected by French botanist Jacques Labillardière in 1792–93, Telopea truncata was first scientifically described in 1805. Genetic analysis revealed that the Tasmanian waratah is the most distinctive of the five waratah species. It can be cultivated in temperate climates, requiring soils with good drainage and ample moisture in part-shaded or sunny positions. Several commercially available cultivars that are hybrids of T. truncata with the New South Wales waratah (T. speciosissima) and Gippsland waratah (T. oreades) have been developed.

The Tasmanian waratah is a large erect shrub up to 3 metres (10 ft) in height with several stems, although it sometimes grows as a single-stemmed tree to 10 m (35 ft) high. Unlike the New South Wales waratah (T. speciosissima), which has a few stems topped with flowers, the stems of the Tasmanian waratah branch freely, with numerous smaller branches topped with flower heads. Younger branches and flower heads frequently have a coating of brownish hairs. The narrow adult leaves are 3–14 cm (1+185+12 in) long and 0.5–2.2 cm (1478 in) across and have a rough texture. Spathulate (spoon-shaped) to obovate in shape, they have smooth, slightly down-curved margins. The undersurface of the leaves is hairy. Occasional lobed leaves are seen.

Flowering occurs from October to January, and is related to altitude: plants at lower elevations flower earlier than ones higher up. The flower heads, known as inflorescences, are terminal—that is, they arise on the ends of small branches—and are surrounded by small inconspicuous hairy bracts. This sets T. truncata apart from all other waratah species, which have hairless bracts. In the shape of a flattened raceme, the flower heads are 3.5–6 cm (1+382+38 in) in diameter and composed of 10 to 35 individual flowers. They are most commonly bright red, though scattered yellow-flowered plants occur. These were described as forma lutea but are mere colour variations and not genetically distinct. Yellow-flowered plants have both red- and yellow-flowered progeny. Anthesis is basipetal; that is, the flowers at the base (edges) of the flower head open first. The flower is composed of a 2 cm-long perianth on a 1 cm-long stalk, with a pronounced kink in the style above the ovary; all other waratah species have gently incurving styles. Anatomically, the individual flower bears a sessile anther (that is, it lacks a filament), which lies next to the stigma at the end of the style. The ovary lies at the base of the style and atop a stalk known as the gynophore, and it is from here that the seed pod then develops. Meanwhile, a crescent-shaped nectary lies at the base of the gynophore.

After flowering, the curved leathery to woody follicles develop. Hanging downwards on wooden stalks, these are roughly oblong in shape, and measure around 5 cm (2 in) long. They split longitudinally to release the winged seeds, which are ripe around March. There are around 16 seeds, which are arranged in two rows. Wooden structures known as lamellae separate the seeds from each other and the follicle walls.

While exploring Van Diemen's Land (Tasmania) in 1792–93, French botanist Jacques Labillardière collected specimens of what he later formally described as Embothrium truncatum in his 1805 work Novae Hollandiae Plantarum Specimen. The specific epithet is the Latin adjective truncatus, meaning "truncated" or "ending abruptly", referring to the end of the seed wing. This characteristic is not specific to the Tasmanian waratah; all members of the subtribe Embothriinae have truncate seed wings. Embothrium was a wastebasket taxon at the time, and Robert Brown proposed placing the species in a new genus, Telopea, in a talk he gave in 1809, publishing the new name Telopea truncata in 1810. Richard Salisbury had attended the talk and controversially published the species as Hylogyne australis, or southern hylogyne, in Joseph Knight's 1809 book On the cultivation of the plants belonging to the natural order of Proteeae, thus claiming precedence over Brown's formal 1810 description. Salisbury was involved in disputes with several prominent naturalists of the time, and his preemption of Brown was seen as unethical, so his names were largely ignored by his contemporaries in favor of Brown's.

James Ross described a new species of waratah, Telopea tasmaniana, in his Hobart Town Almanack in 1835, but it is now considered a synonym of T. truncata. In 1891, German botanist Otto Kuntze published Revisio generum plantarum, his response to what he perceived as a lack of method in existing nomenclatural practice. He revived the genus Hylogyne on the grounds of priority, and correctly made the new combination Hylogyne truncata for T. truncata. However, Kuntze's revisionary program was not accepted by the majority of botanists. Ultimately, the genus Telopea was nomenclaturally conserved over Hylogyne by the International Botanical Congress of 1905.

Telopea truncata is one, and possibly the most distinctive, of five species from southeastern Australia which make up the genus Telopea. It is the earliest offshoot of a lineage that gives rise to the Gippsland waratah (T. oreades) and Monga waratah (T. mongaensis) of southeastern mainland Australia. The perianths of T. truncata are of a single shade of red, whereas those of its mainland relatives are coloured with two distinct shades of red—the surfaces facing the centre of the flower head are a much brighter red than those facing away.

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