Eucalyptus cometae-vallis       0

Author: Joseph Henry Maiden (1859-1925)
Family: Myrtaceae Subfamily: Myrtoideae Tribe: Eucalypteae
Genus: Eucalyptus Subgenus: Symphyomyrtus Section: Dumaria Serie: Ovulares
Synonym(s): Eucalyptus brachycorys
English name: Comet Vale mallee
Zone: Australia

Description
This mallee is endemic to western Australia, on the northern sandy plains and central wheat belt east of Mullewa Coorow, Cowcowing Lakes and Merredin. It also occurs sporadically in drier goldfields further east and north, for example near Barlee Lake, Menzies, Cosmo Newberry, Queen Victoria Springs. The origin of its name Eucalyptus brachycorys comes from the Greek ‘brachy’ which means short, and ‘korys’, which means helmet referring to the short operculum. It grows in yellow, red or brown sand soils. It is suitable for arid and semi-arid climate and can adapt to regions with hot temperatures. It is tolerant of acid and alkaline soil, and to light frosts.
Eucalyptus cometae-vallis Observed in Australia by Dean Nicolle (license)
Botanical Description
This Eucalyptus is a mallee and forms a lignotuber. The bark is rough, gray, shaggy to ribbony on part or all of the trunk and on the branches of 10cm in diameter. On smaller mallees, the bark is smooth and pinkish-gray to whitish and yellow-green.

The stems are rounded or square in cross section. The juvenile leaves are always petiolate, alternate, lanceolate. They measure 5.5 to 8cm long and 1 to 2cm wide. The juvenile leaves are dull, gray-green in color. The adult leaves are alternate, petiolate 0.8 to 1.5cm long. The blade is linear to narrowly lanceolate, measuring 6 to 10cm long and 0.6 to 1.5cm wide. The base is tapering to the petiole, the margin is entire and the apex pointed. The color of the leaves is concolorous, bright, green.

The inflorescence is unbranched axillary, with a peduncle measuring 0.6 to 1.2cm long and composed of 7 to 9 or 11 buds per umbel, with pedicel which measures 0.2 to 0.6cm long. The mature buds are cylindrical to closely pyriform and measure 0.6 to 0.9cm long by 0.3 to 0.5cm wide, always with constriction at the join of the hypanthium and the operculum. The scar is present, the operculum is rounded to flattened with a conspicuous but short beak 0.15 to 0.3cm long. The stamens are inflexed, the anthers are oblong, versatile, dorsifixed, dehiscing by longitudinal slits, the style is long and straight, the stigma broadly rounded to tapered. 3 or 4 locules present. The flowers are white from February to April.

The fruit is pedicelled from 0.2 to 0.8cm long, barrel-shaped, obconical, or cupular, from 0.5 to 0.8cm long by 0.5 to 0.7cm wide, 3 to 4 valves at rim level. The seeds are brown and 0.5 to 1.8mm long, flattened-ovoid with dorsal surface shallowly and clearly reticulated, ventral hilum.
Member of
The Genus: Eucalyptus Subgenus: Symphyomyrtus Section: Dumaria Serie: Ovulares having the following characters: The buds have two opercula, stamens are strongly inflexed, ovules are in 4 rows on the placentae and cotyledons are reniform. Within section Dumaria Eucalyptus cometae-vallis belongs to a small sub-group of nine closely related species which are together called series Ovulares. The series is further diagnosed by glandular pith, cuboid anthers, and seeds with a brown shallowly and clearly reticulate dorsal seedcoat.
Useful plant
The trunk is not commercially important, but its flowers are appreciated by beekeepers. This eucalyptus is used in gardens, parks, roadsides, as a small windbreaker and to control wind erosion.

References
- Encyclopedia of Australian Plants, Elliot W. Rodger & Jones David L. 2012 Vol. 4 pag. 59. ISBN
- Eucalypts of Australia. Eucalyptus cometae-vallis
- Notes on Eucalyptus brachycorys Blakely and E. comitae-vallis Maiden, Brooker, M. I. H. (Murray Ian Hill),. Nuytsia 1974 Vol. 1 pag. 294-296. Address
References for the genus
- Encyclopedia of Australian Plants, Elliot W. Rodger & Jones David L. 2012. ISBN
- Seeds of woody plants in the United States, Schopmeyer Clifford Scharff and others. 1974 pag. 384-392. Address
- A general history of the dichlamydeous plants, comprising complete descriptions of the different orders, Don, George. 1831 Vol. 2. Address
- A new classification of sections and series in Eucalyptus subg. Eudesmia (Myrtaceae), Bayly, Michael and Mclay, Todd and Cantrill, David and Fowler, Rachael. Muelleria: An Australian Journal of Botany 2023 Vol. 41 pag. 50-54. DOI
- A new series, Incognitae, of Eucalyptus L'Her., including a new species endemic to Fleurieu Peninsula and Kangaroo Island, South Australia, Nicolle, D. Journal of the Adelaide Botanic Garden 1995 pag. 73-78. JStor
- A new species and a new combination in the shining peppermint group of Eucalyptus and notes on the distribution of Eucalyptus willisii sens. strict, Rule, K. Muelleria: An Australian Journal of Botany 2008 Vol. 26. DOI
- A revision of the Yellow Bloodwoods (Myrtaceae: Eucalyptus ser. Naviculares Maiden), Brooker, M.I.H and Bean, Tony. Austrobaileya 1991 Vol. 3 pag. 409-437. DOI
- A taxonomic revision of Eucalyptus wandoo, E. redunca and allied species (Eucalyptus series Levispermae Maiden - Myrtaceae) in Western Australia, Brooker, M. I. H. (Murray Ian Hill), and Hopper, Stephen D. Nuytsia 1991 Vol. 8 pag. 1-189. Address
- Eucalyptus revelata, a rare new species related to E. mooreana (Myrtaceae) from the Kimberley region of Western Australia, Nicolle, Dean and Barrett, Russell L and others. Nuytsia 2018 Vol. 29 pag. 109-118. Address
- Eucalyptus wimmerensis revisited and notes on the morphologies and taxonomies of five Victorian mallee-boxes, Rule, K. Muelleria: An Australian Journal of Botany 2018 Vol. 37 pag. 39-64. DOI
- Five new endemic eucalypts for Victoria, Rule, K. Muelleria 2012 Vol. 30 pag. 83-105. DOI
- Four new species of Eucalyptus, S. T. Blake. Austrobaileya 1977 Vol. 1(1) pag. 1-9. JStor
- Four new species of ironbark (Eucalyptus L'Herit., Myrtaceae) from southern Queensland, Bean, Tony and M.I.H.Brooker,. Austrobaileya 1994 Vol. 4 pag. 187-194.
- Multivariate analysis of morphological variation in Eucalyptus series Psathyroxyla Blakely (Myrtaceae): taxonomic implications, Pfeil, BE and Henwood, MJ. Telopea 2004 Vol. 10(3) pag. 711-724. Address
- New subspecies in Eucalyptus caesia and in E. crucis (Myrtaceae) of Western Australia, Brooker, M. I. H. (Murray Ian Hill), and Hopper, S D. Nuytsia 1982 Vol. 4 pag. 113-128. Address
- New taxa and combinations in Eucalyptus and Angophora (Myrtaceae), Johnson, Lawrence and Hill, Kenneth. Telopea 1990 Vol. 4 pag. 37-108. DOI
- New taxa in Eucalyptus (Myrtaceae) for Victoria and notes on Victorian populations of Eucalyptus calycogona, Rule, K. Muelleria 2004 Vol. 20 pag. 9-32. DOI
- New taxa of Eucalyptus informal subgenus Symphyomyrtus (Myrtaceae), endemic to South Australia, Nicolle, Dean. Journal of the Adelaide Botanic Garden 2000 pag. 83-94. JStor
- Notes on Eucalyptus ser. Psathyroxyla Blakely (Myrtaceae) and other 'Ash group' eucalypts, Bean, Tony. Austrobaileya 1997 Vol. 5 pag. 125-135. DOI
- Notes on the narrow-leaved Ironbarks (Myrtaceae: Eucalyptus subseries Subglaucae), Bean, Tony. Austrobaileya 2005 Vol. 7 pag. 111-120. DOI
- Resolution of a 35-year taxonomic dilemma: Eucalyptus sp. Howes Swamp Creek (Myrtaceae) from eastern Wollemi National Park, New South Wales, Bell, Stephen and Phillips, Gavin and Nicolle, Dean. Telopea 2022 Vol. 25 pag. 151-163. DOI
- Six new infraspecific taxa in Eucalyptus (Myrtaceae) for Victoria, Rule, K. Muelleria 2011 Vol. 29 pag. 3-15. DOI
- Systematic studies in the eucalypts — 3 New taxa and combinations in Eucalyptus (Myrtaceae), Hill, Kenneth & Johnson, L. A. S. Telopea 1991 Vol. 4(2) pag. 223-267. Address
- Systematic studies in the eucalypts — 4 New taxa in Eucalyptus (Myrtaceae), K.D. Hill & L-A.S. Johnson. Telopea 1991 Vol. 4(2) pag. 312-349. Address
- Systematic studies in the Eucalypts 5. new taxa and combination in eucalyptus myrtaceae in western australia, Hill, K.D.; Johnson, L.A.S. Telopea 1992 Vol. 4(4) pag. 561-634. Address
- Systematic studies in the eucalypts. 10. New tropical and subtropical eucalypts from Australia and New Guinea (Eucalyptus, Myrtaceae), Hill, KD and Johnson, LAS. Telopea 2000 Vol. 8(4) pag. 503-539. Address
- Systematic studies in the eucalypts. 6. A revision of the coolibahs, Eucalyptus subgenus; Symphyomyrtus section; Adnataria series; Oliganthae subseries; Microthecosae (Myrtaceae), Hill, KD and Johnson, LAS. Telopea 1994 Vol. 5(4) pag. 743-771. Address
- Systematic studies in the eucalypts. 8. A review of the eudesmioid eucalypts, Eucalyptus subgenus Eudesmia (Myrtaceae), Hill, KD and Johnson, LAS. Telopea 1998 Vol. 7(4) pag. 375-414. Address
- Systematic studies in the Eucalypts. 9. A review of series Sociales (Eucalyptus subgenus Symphyomyrtus, Section Bisectaria, Myrtaceae), Hill, K.D. and Johnson, L.A.S. Telopea 1999 Vol. 8 (2) pag. 165-218. Address
- Taxonomic and nomenclatural notes on the Eastern grey boxes (Eucalyptus ser. Moluccanae Chippendale, Myrtaceae) and the reinstatement of Eucalyptus woollsiana R.T.Baker, Bean, Tony. Austrobaileya 2009 Vol. 8 pag. 25-34. DOI
- The Ironbarks Allied to Eucalyptus crebra F. Muell. and the Description of a New Species, E. quadricostata, in the Group, Brooker, M. Austrobaileya 1985 Vol. 2 pag. 148-152. DOI
- Three new Victorian species related to Eucalyptus aromaphloia L.D. Pryor and J.H. Willis and notes on the polymorphic nature of that species, Rule, K. Muelleria: An Australian Journal of Botany 1996 Vol. 9 pag. 133-143. DOI
- Two new mallee Eucalypts (Myrtaceae) from Gippsland, Victoria, Rule, K. and Molyneux, W.M. Muelleria 2011 Vol. 29 pag. 16-26. DOI
- Two new subspecific taxa within the Eucalyptus Series Argyrophyllae for Victoria, Rule, Kevin and Walsh, Neville. Muelleria: An Australian Journal of Botany 2017 Vol. 36 pag. 81-91. DOI
- Typification of some names in Eucalyptus (Myrtaceae), Part 1, Bean, Tony. Telopea 2009 Vol. 12 pag. 309-319. DOI
- Typification of some names in Eucalyptus (Myrtaceae), Part 2, Bean, Tony. Telopea 2010 Vol. 12 pag. 469-477. ResearchGate
- Typification of some names in Eucalyptus (Myrtaceae), Part 3, Bean, Tony. Telopea 2010 Vol. 12 pag. 511-520. ResearchGate
- Hommes et Plantes. Vol. 58 pag. 34-41. Address
- PlantÆxoticA. 2015 Vol. 28 pag. 18-26. Address
- PlantÆxoticA. 2015 Vol. 21 pag. 4-19. Address
- PlantÆxoticA. 2015 Vol. 11 pag. 7-11. Address
- Vegetative propagation of Eucalyptus through cuttings, Banthia K. M., Joshi C. M., Venkata Reddy P. B. & Sinha J. P. Indian Pulp & Paper Technical Association 1988 Vol. 25(1) pag. 37-40. Address
General specifications
Biological type: tree
Frost resistance: 14ºF
Leaf color: dark green
Flower color: white
No transplantation: Yes
Reproduction mode: hermaphrodite plant whoes flowers produce both male and female gametes

Specifications for the Mediterranean basin
Adult size (h x w): 26,2ft x 13,1ft
Sun exposure: full sun (Sun hours: >6h
Foliage: evergreen
Growth: fast
Flowering time from August until October

Specific information for our garden
Planting substrate: 30%Compost+30%Coco+40%Sand
Plant watering: 1x a week pH 5.5
Logical sequence of containers for: Eucalyptus; forestry plate, forestry pot 3L, Airpot 12L, Airpot 50L, Airpot 800L
Propagation is done by cuttings

Ecology in its country of origin
Rainfall: 100-300mm
Clay soil: much
Sandy soil: much
Limestone soil: a little
Acidic soil: much
Draining soil: much
Sowing instructions
SPRING Select the largest and most fleshy BROWN seeds. Sow the seeds at 2mm depth in the Well Drained Seed Sowing Mix between 59-68°F. During germination keep the substrate moist and in daylight. The seeds germinate in 3-6 weeks. The viability of the seeds, kept under good conditions, is 10 years.
The average seed weight is 546,4 per gram (0,00183g).

Germination references for the genus
- Seeds of woody plants in the United States, Schopmeyer Clifford Scharff and others. 1974 pag. 384-392. Address
- Eucalypt seed and sowing. Native Forest Silviculture Technical Bulletin 2010 Vol. 1. Address
- USDA Forest Service's Woody Plant Seed Manual, John K. Francis and Craig D.Whitesell. 2008. Address

Experiences in the garden
14-02-19A Obtaining seeds from seed provider Nindethana Seeds collected in '....'. (Cultivated from unknown origin)
03-03-20 Send a batch to nursery Railhet.
16-03-20 Sown 30 seeds in a seed plate F, they did not geminate in Serre3.
Protocol: Spring 2mm Sowing mix+Sand 59-68°F Damp substrate+Light 3-6w
10-03-21 Sown 30 seeds in a seed plate F, they did not geminate in Serre3.
Protocol: Spring 2mm Sowing mix+Sand 59-68°F Damp substrate+Light 3-6w
10-05-22 Sown 30 seeds in a seed plate F, they did not geminate in Serre3.
Protocol: Spring Straw colored Seed 2mm Sowing mix+Sand 68-77°F Damp substrate+Light 3w
14-03-23 Sown 3 seeds in a seed plate F, they did not geminate in Serre3.
Protocol: Spring Straw colored Seed 2mm Sowing mix+Sand 59-68°F Damp substrate+Light 3-6w