A new species of Melaleuca (Myrtaceae) from northern Queensland, Australia



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A new species of Melaleuca (Myrtaceae) from northern

Queensland, Australia

L.A. Craven

1,3


and A.J. Ford

2

1,3



Australian National Herbarium, CPBR, CSIRO Plant Industry, GPO Box 1600,

Canberra, ACT 2601, Australia

2

CSIRO Sustainable Ecosystems and Rainforest CRC, P.O Box 780, Atherton, Qld 4883



Australia

3

author for correspondence



Abstract

Melaleuca sylvana Craven & A.J. Ford is described from the Herberton-Ravenshoe area in northern

Queensland. A key to the microphyllous species of Melaleuca in northern Queensland is provided.



Introduction

During field studies in northern Queensland by the first author in 2001, the second author

drew attention to an unusual microphyllous Melaleuca  that occurred in the Herberton

region on the western edge of the Atherton Tableland. The population was visited and

specimens collected for later study in the herbarium. In the field it was observed that the

plants were superficially similar to M. monantha (Barlow) Craven but differed from that

species in having, inter alia, a more typical tree-like habit and larger fruit. Melaleuca

monantha typically occurs as densely crowned, multistemmed plants although some

collectors have noted on specimen labels that the plants were trees (but without indicating

whether they were multibranched or not). The Herberton plants we observed were

sparsely crowned and single-stemmed.

Subsequent comparison of the Herberton material with herbarium specimens of M.

monantha established that they differed in a number of characters. The more distinctive

of these are listed in Table 1. In view of these differences, which are consistent with, if

not exceeding, differences accepted for species segregation in other Melaleuca

complexes in the Flora of Australia account of the genus (Craven et al. in press), it is

concluded that the Herberton specimens represent a previously unknown species of

Melaleuca, described below as M. sylvana.

Taxonomy

Melaleuca sylvana Craven & A.J. Ford, sp. nov.

A  M. monantha (Barlow) Craven hypanthio longiore (2-2.2 mm longo), filamentis

staminalibus longioribus (7-8.5 mm longis), stylo longiore (8-10 mm longo), et hypanthio

in fructu longiore (4-4.25 mm longo) differt.



Type: Australia: Queensland: Cook District: Powerline access road, W of Herberton,

c. 1.85 km along road from the Herberton-Watsonville road, 6 December 2001, Craven



& Ford 10430 (holotype BRI; isotypes A, ASU, B, BISH, CANB, E, G, L, MEL, NSW,

P, US).


Tree or shrub to 5 m tall, open-crowned. Bud scales absent. Branchlets glabrous, terete,

excavated (i.e. impressed) adjacent to the leaf blade. Leaves decussate, imbricate,

amplexicaul, peltate, ascending (blade is appressed proximally at the point of attachment

to the branchlet but is ascending distally), distinctly dorsiventral, 1.5-3.7 mm long, 0.9-1.7

mm wide, 1.4-2.3 times as long as wide, sessile; leaf blade glabrescent, the indumentum

Muelleria 20: 3–8 (2004)


with minute very ephemeral puberulous hairs on the distal abaxial surface and deciduous

cilia on the margin, dull-glossy to dull, greenish or brownish, obovate or broadly obovate

(to obovate-elliptic), in transverse section lunate (i.e. concavoconvex), sublunate or

strongly so, in lateral view straight to recurved (the apex slightly incurved), the base

truncate, the apex truncately acuminate to obtusely and shortly acuminate or acuminate,

the 7-11 veins parallel; oil glands moderately dense to sparse, distinct or obscure, circular.



Inflorescence a head or short spike of (1-)2-10 monads inserted interstitially in the median

to distal axils of the reproductive seasonal growth flush, 8-18 mm wide, the rachis

puberulous, each monad subtended by a foliage leaf and the flower by a pair of bracteoles.

Hypanthium glabrous, pale orange, costate-cylindrical to cup-shaped, proximally not

compressed, 2-2.2 mm long, 1.9-2 mm wide. Calyx lobes 5, abaxially glabrous, costate,

herbaceous in the proximal-central zone and scarious in a narrow marginal band 0.1-0.2

mm wide, the margin ciliate, very broadly ovate to very broadly triangular, 0.8-1 mm long,

persistent at least until the immature fruit stage. Petals deciduous, glabrous, pure white,

sometimes flushed cream, distinctly but very shortly clawed, subcircular, 2 mm long,

margin ciliate; oil glands circular. Stamens in 5 bundles, imperfectly 2-seriate, 9-12 per

bundle, staminal ring absent; filaments glabrous, pure white, 7-8.5 mm long, the bundle

4

Craven and Ford



Table 1. Differences between two species of Melaleuca

Character

M. monantha

M. sylvana

Habit 


Densely foliaged shrub or tree 

Open shrub or tree to 5 m tall

to 7 m tall

Leaf hairs 

Spreading 

Ascending

Leaf blade 

Angular-obovate 

Rounded-obovate (never angular)

Leaf blade vein number 

5-7 

7-11


Hypanthium 

1.3-1.8 by 1.1-1.3 mm 

2-2.2 by 1.9-2 mm

Calyx lobes 

0.5-0.7 mm long 

0.8-1 mm long

Petals 

Obscurely clawed



Distinctly clawed

Petals 


1.2-1.6 mm long 

2 mm long

Petals 

Oil glands absent 



Oil glands present

Staminal filaments 

4.5-6.8 mm long 

7-8.5 mm long

Staminal bundle claw

2-3.5 mm long 

4.25-4.5 mm long

Staminal filaments 

Free portion inserted in the   

Free portion inserted in the distal 

distal half to three-quarters of 

quarter of the bundle claw

the bundle claw

Anthers


0.2-0.3 mm long 

0.4-0.6 mm long

Style 

5-6 mm long 



8-10 mm long

Ovules 


20 per locule 

27-30 per locule

Infructescence 

6 mm in diameter 

9 mm in diameter

Fruiting hypanthium 

2-3.2 by 2.5-4 mm 

4-4.25 by 4.25-5 mm

Seed 

0.8-0.9 mm long 



1.1-1.3 mm long

Cotyledons c. 

1/2 the length of the embryo c. 

1/3 the length of the embryo



claw 4.25-4.5 mm long and 0.5-0.6 times as long as the filaments, the free part of the

filaments inserted on the claw margin only and in the distal quarter of the claw; anthers

generally uniform in size, oblong, 0.4-0.6 mm long, the connective not prominently

glandular.  Ovary wall adnate to the hypanthium for the proximal one-quarter only;

placentation axile-median (although very near the base of the locule); ovules 27-30 per

locule. Style glabrous, straight or more or less so, 8-10 mm long, the stigma punctiform.



Infructescence longer than wide to shorter than wide, 9 mm in diameter. Fruiting

hypanthium subglobose, depressed subglobose or urceolate, 4-4.25 mm long, 4.25-5 mm

wide, 0.8-0.9 times as long as wide, 2-2.5 mm wide at the orifice; calyx lobes replaced by

sepaline teeth; staminophore not prominent, the inner distal wall of the staminophore with

5 reflexed free antesepalous triangular processes; valves inserted. Seed angular narrowly

obovoid to narrowly obovoid, 1.1-1.3 mm long, the testa membranous; embryo with the

cotyledons about one third its length, the cotyledons obvolute.



Etymology: The epithet is derived from the Latin sylva, wood, forest, woodland, in

reference to the habitat in which this species is commonly found.



Phenology: Flowering period: December. Fruits apparently present in all months

(collected in February, March, June and December).



Other specimens examinedAUSTRALIAQUEENSLAND: COOK District: Baal Gammon,

29 March 1980, Hyland 10370 (QRS); 3 June 1997, Forster, Booth & Jensen 21214 (BRI). Toys

Creek, W of Herberton, powerline access road, 4 February 1996, Forster & Ryan 18443 (CANB);

June 1996, Ford 1739 (CANB, QRS); 25 May 1997, Sankowsky & Sankowsky 1576 (BRI); 25 July

1998, Bean 13732 (BRI). NORTH KENNEDY District: Mt Ronald, S of Ravenshoe, 23 December

1998, McDonald s.n. (AQ666176) (BRI). Mt. Ronald road, off Wooroora road, SW of Ravenshoe,

27 January 2004, Ford & Hewett 4286 (BRI, CANB).

Distribution and ecologyMelaleuca sylvana has been recorded from two regions in

the Herberton-Ravenshoe area on the western and southern side of the Atherton



Melaleuca

5

Figure. 1. Distributions of Melaleuca species. The inset map of Australia shows the entire

distribution of M. monantha.


Tableland, on the Wet Tropics-Einasleigh Uplands bioregional boundary, at altitudes of

(800-)1020-1050 m (Fig. 1). It has been recorded as occurring in open forest, in heath on

rhyolite, in low open woodland of Eucalyptus abergiana and  E. shirleyi with a closed

heathland of Melaleuca and Micromyrtus on weathered rhyolite, in Casuarina inophloia-



Callitris-eucalypt woodland on rhyolite, and in grassy woodland of Eucalyptus

citriodoraE. crebra and E. mediocris on soil derived from rhyolite.

Conservation statusMelaleuca sylvana is currently not recorded in any protected

area and lies outside the World Heritage Area of northeastern Queensland. We

recommend that a detailed search be undertaken in adjacent habitats to fully assess the

conservation status of this poorly known species.



Notes: The species is closely related to M. monantha from which it differs, inter alia,

in the features given in Table 1. Also, M. monantha typically occurs in flat to slightly

undulating areas at altitudes less than 700 m and on poorly drained soils with impeded

drainage that suffer prolonged seasonal inundation. In contrast, M. sylvana typically

occurs on steep rocky hillsides at altitudes above (800-)1000 m and the soils, although

poorly drained, would rarely if ever experience inundation. Melaleuca sylvana has been

observed to resprout after fire, with profuse epicormic and lignotuber shoots. In such

instances the habit of the plant is more shrubby and less tree-like as a result of the

periodic exposure to burning.

In the identification keys given in Craven & Lepschi (1999), M. sylvana keys out in

Key 1 to Mmonantha (Barlow) Craven. It may be inserted into Key 1 by replacing the

second lead of couplet 6 with the following:

6a. Hypanthium 1.3-1.8 mm long; staminal filaments 4.5-6.8 mm long; style 5-6 mm

long; fruiting hypanthium 2-3.2 mm long....................M. monantha (Barlow) Craven

6a. Hypanthium 2-2.2 mm long; staminal filaments 7-8.5 mm long; style 8-10 mm long;

fruiting hypanthium 4-4.25 mm long ..........................M. sylvana Craven & A.J. Ford

It is noteworthy that M. sylvana is the third species of the M. minutifolia F. Muell.

species group to be recorded from the Atherton Tableland (Herberton Range) area.



Melaleuca monantha was the first species to be recognised from this area (Craven &

Lepschi 1999) and M. uxorum Craven, G. Holmes & Sankowsky the second (Craven et



al. 2004). The distributions of the three species are shown in Fig. 1. This biological

richness may be due in part to the environmental diversity experienced towards the

western side of the Tableland; here altitude, climate and geology interact to produce

considerably different localised vegetation types which in turn may foster evolutionary

activity leading to speciation in lineages such as the present Melaleuca example.

Melaleuca sylvana co-occurs with other significant and localised northern Queensland

sclerophyllous endemic species such as Micromyrtus delicata and Homoranthus porteri.

The Herberton Range is well known also for harbouring a distinctive warm-temperate

floristic element in an otherwise tropical landscape. This is due to the elevation and the

distance from maritime influences, which creates a more varied and extreme climate that

is more similar to the Sydney Basin (for example) than the nearby tropical rainforested

hillsides. The warm-temperate element includes such species as Chorizema parvifolium,

Melichrus urceolatus and Mirbelia speciosa.

Key to the microphyllous species of Melaleuca in Queensland north of Lat. 20° S

1.  Leaves more than 5 mm long ............................... non-microphyllous Melaleuca spp.

1.

Leaves less than 5 mm long



2. Leaves decussate

3. Flowers in triads  ........................M. uxorum Craven, G. Holmes & Sankowsky

3. Flowers in monads

6

Craven and Ford



4.  Branchlets hairy; style 1.5-2 mm long ......M. foliolosa A. Cunn. ex Benth.

4.  Branchlets glabrous; style 5-10 mm long

5.  Hypanthium 1.3-1.8 mm long; staminal filaments 4.5-6.8 mm long;

style 5-6 mm long; fruiting hypanthium 2-3.2 mm long  .......................

................................................................M. monantha (Barlow) Craven

5.  Hypanthium 2-2.2 mm long; staminal filaments 7-8.5 mm long; style 8-

10 mm long; fruiting hypanthium 4-4.25 mm long  ...............................

...............................................................M. sylvana Craven & A.J. Ford

2. Leaves alternate

6.  Hypanthium glabrous; leaves sessile and peltate; trunk and major branch bark

fibrous ...........................................................................M. tamariscina Hook.f.

6. Hypanthium usually hairy (rarely glabrescent); leaves sessile but not peltate;

trunk and major branch bark papery ..............................M. bracteata F. Muell.

Acknowledgments

The Directors and/or Curators of the following herbaria are thanked for the opportunity

to study collections in their care: BRI, CANB, QRS. Tony Bean kindly examined some

material in BRI on our behalf, and Paul Forster expedited the loan of specimens. Keith

McDonald (EPA, Atherton) is thanked for giving directions to the Mt Ronald population.

Trevor Parker (CSIRO, Atherton) provided invaluable assistance with preparation of the

distribution maps.

References

Craven, L.A. and Lepschi, B.J. (1999). Enumeration of the species and infraspecific taxa of



Melaleuca (Myrtaceae) occurring in Australia and Tasmania. Australian Systematic Botany 12:

819-927.


Craven, L.A., Holmes, G. and Sankowsky, G. (2004, as 2003). Melaleuca uxorum (Myrtaceae), a

new species from north-eastern Australia. Muelleria 18: 3-5.

Craven, L.A., Lepschi, B.J., Barlow B.A. and Cowley, K.J. (in press). Melaleuca. In ‘Flora of

Australia’.



Melaleuca

7

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