Pherosphaera

W. Archer bis 1850

Common names

Taxonomic notes

A genus of two species:

• Pherosphaera fitzgeraldi
• Pherosphaera hookeriana (type species)

Syn: Microstrobos J. Garden et L.A.S. Johnson 1951. This genus, and the closely related monotypic genus Microcachrys, are comprised of shrubby Australian species with very small scale-like leaves and very small cones; the three have frequently been confused by botanists, resulting in a legacy of misidentification and a tangled nomenclature; to read whole story, see Brummitt et al. (2004).

Description

Evergreen dioecious shrubs. Branches short and stiff or long and slender. Leaves of adult and juvenile plants similar. Adult leaves spirally arranged but often seemingly in 4 or 5 rows, keeled, <4 mm long. Scale-like leaves imbricate and obtuse, awl-like leaves spreading and acute. Cones (pollen and seed) solitary, terminal on normal vegetative shoots. Seed cones not fleshy at maturity, ovoid to globose, epimatium lacking, ovules erect, about 2.5 mm long with 3-8 fertile scales, scales thin, thickened at the base, obovate, brown when mature. Pollen cones 2-3 mm long, composed of 8 - 15 stamens. Seeds several in each cone, each seed at the base of a glume-like scale equalling or slightly exceeding the length of the seed. Individual seeds light brown or greyish, up to about 1 mm diameter, with a hard, glossy brown integument. 2n=26 (Dallimore et al. 1967, Hill 1998).

The following key is provided by Hill (1998):

Adult leaves to 1.5 mm long, fully appressed to the stem, less than twice as long as wide, native to Tasmania.	P. hookeriana
Adult leaves 2.5-3.5 mm long, free and spreading, basally decurrent, more than twice as long as wide, native to New South Wales.	P. fitzgeraldi

Distribution and Ecology

Australia: New South Wales and Tasmania (each with one endemic species) (Harden 1990). Found at alpine elevations usually on mesic sites such as the margins of lakes, streams, and waterfalls, where they are rare (Dallimore et al. 1967).

Remarkable Specimens

No data as of 2023.02.21.

Ethnobotany

Almost unknown. Although both species are rare in cultivation, they likely have potential value in horticulture.

Observations

See the species accounts.

Remarks

The genus name is derived from the Greek words for "I bear" and "globe", in reference to the globose seeds.

Citations

Archer, W. 1850. Hooker's J. Bot. Kew Gard. Misc. 2:52. Available: Biodiversity Heritage Library, accessed 2022.12.24.

Brummitt, R.K., R.R. Mill and A. Farjon. 2004. The significance of 'it' in the nomenclature of three Tasmanian conifers: Microcachrys tetragona and Microstrobos niphophilus (Podocarpaceae), and Diselma archeri. Taxon 53(2):529-539.

Garden, J. and L. A. S. Johnson. 1951. Microstrobos, a new name for a Podocarpaceous genus. Contr. New South Wales Natl. Herb. 1:315-317.

See also