Milligania

Milligania
Milligania densiflora
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Monocots
Order:	Asparagales
Family:	Asteliaceae
Genus:	Milligania Hook. f.
Species
See text.

Milligania is a genus of native perennial plants containing five species which are all found in Tasmania:^{[1][2][3][4][5]}

• Milligania densiflora Hook.f.
• Milligania johnstonii F.Muell. ex Benth.
• Milligania lindoniana Rodway ex W.M.Curtis
• Milligania longifolia Hook.f.
• Milligania stylosa (F.Muell. ex Hook.f.) F.Muell. ex Benth.

Formerly belonging to the Liliaceae family, Milligania is now a part of the Asteliaceae family.^[4] Three of these species are alpine and subalpine, with the remaining two rare species growing along rivers in the south-west of the state.^[4] All five species are restricted to very wet habitats and are typically found growing on waterlogged peat.^[4] They are known to form extensive rough mats. ^[4]

Description

Plants within this genus are perennial, rhizomatous, tufted herbs with short stems, often forming small clumps.^[6][7][8][9]

Leaves

The broad, leathery leaves exhibit a triangular shape with pleats resembling those found in the Astelia genus.^[4][6] Leaves are alternately arranged^[8] and sizes vary from quite small, measuring less than 5 cm in length, to large specimens reaching up to 1.25 m in length.^[4] These leaves are sheathing in structure, with some silky hairs.^[7]

Flowers and reproduction

The star-like flowers boast six tepals and are prominently displayed in inflorescences above the leaves.^[4][6] The flowers are pedicellate with basally fused tepals^[9] which are primarily white, occasionally tinged with red at the tube mouth, with dense silky hairs that are rare in Aparagales.^[7][8] These inflorescences can reach heights of up to 50 cm, with flowers densely arranged in a panicle formation.^[7] Each flower, measuring up to 1.5 cm wide, is abundant and spreading during the summer season.^[7] Milligania species are all hermaphroditic and produce bisexual flowers.^[11]

Fruit and seeds

Milligania has a dry capsule fruit containing several seeds^[9] which contrasts to the fleshy fruit commonly found in the genera Astelia and Neoastelia in the Asteliaceae family.^[4][5][8] Milligania, and some Astelia species possess trilocular ovaries. ^[8] Skottsberg proposed that features such as the capsular fruit, bisexual flowers and simple hairs observed in Milligania are primitive traits, or plesiomorphic.^[11] Milligania was considered to be divergent from other genera within the Asteliaceae family due to its semi-inferior ovary and dry fruit.^[12]

Roots

Thickened, fleshy roots from a short thick rhizome.^[7]

Distribution and Habitat

While Asteliaceae taxa are distributed across Austral and Pacific regions, the primary centre of generic diversity is situated in Australia.^[8] All five Milligania species are endemic to Tasmania.^[8] According to a distribution map provided by the Atlas of Living Australia, Milligania is mainly distributed on the western side of the state, west of the geographical feature known as Tyler's Corridor.^[14] This divide delineates significant differences in Tasmania's geology, climate, and vegetation.^[14] Geological composition influences soil types, contributing to dramatic variations in vegetation across the state.^[15] The western region typically experiences higher mean rainfall with acidic soils, leading to the prevalence of rainforest, moorland, and wet sclerophyll vegetation.^[15][16] Conversely, the eastern part of the state receives lower mean rainfall and has slightly more fertile soils, resulting in predominantly dry sclerophyll vegetation.^[15][16]

Plants within the Asteliaceae family exhibit a wide range of habitat preferences but generally thrive in environments with consistent moisture levels.^[17] They are commonly found in tall, densely clustered habitats.^[18] The five Milligania species occupy habitats ranging from lowland riparian valleys to alpine fellfields.^[8]

Taxonomy

The genus name 'Milligania' was initially documented in Hooker's J. Bot. Kew Gard. Misc. 5: 296 (1853).^[19] However, its placement within the Asteliaceae family has faced challenges due to insufficient support in a cladistic analysis involving both morphological and molecular data.^[12] It has been regarded as an outlier within the family, diverging from the typical characteristics observed in other genera.^[20] A cladistic study conducted by Maciunas et al. in 2011 revealed a potential sister relationship between the Neoastelia/Milligania and Collospermum/Astelia clades, based on analysis of morphological data.^[21]

Within the Asteliaceae family, studies conducted in 2012 and 2013 grouped Milligania with Astelia.^[8][22] A 2021 study placed Neoastelia and Milligania as sisters:^[23]

Conservation Status and Threats

Milligania johnstonii and Milligania longifolia are listed as rare under the Threatened Species Act 1995.^[24][25] Milligania densiflora is not considered to be at risk in the wild.^[26] There is no known status for Milligania lindoniana or Milligania stylosa.

References

Wikispecies has information related to Milligania .

This page was last edited on 15 April 2024, at 11:06