Luffa saccata F. Muell. ex I. Telford, 2011

Telford, Ian R. H., Schaefer, Hanno, Greuter, Werner & Renner, Susanne S., 2011, A new Australian species of Luffa (Cucurbitaceae) and typification of two Australian Cucumis names, all based on specimens collected by Ferdinand Mueller in 1856, PhytoKeys 5, pp. 21-29 : 24-27

Luffa saccata F. Muell. ex I. Telford sp. nov.

Holotype.

AUSTRALIA. Northern Territory: Baines Creek [=Baines River, a tributary of the Victoria River], May 1856, F. Mueller (MEL000593093!, the fragment pocket contains three seeds; isotypes: K000634638, K000634639, K000634640, the latter with a tag in Mueller’s handwriting ' Luffa saccata Ferd. Mueller. Tropical Australia. Victoria River. May 1856').

A Luffa graveolente floribus masculis longe pedicellatis in racemo elongato dispositis (nec brevissime pedicellatis subfasciculatis) et pedicellis fructiferis quam 15 mm brevioribus (nec plusquam 15 mm longis) differt. Our Figs. 2 and 3 .

Trailing or climbing annual herb, monoecious; stems to 7 m long, 2-3 mm diam., ± glabrous, ribbed. Tendrils 3-5-branched, the stem 4.5-8 cm long, branches 5-9 cm long. Leaves: petiole 1.5-6.5 cm long; lamina ovate to broadly ovate in outline, 3-14 cm long, 2.5-13 cm wide, with 3 or 5 broad rounded or obtuse lobes, the lobes crenate, base cordate with the sinus wide, apex acute, hispid on both surfaces. Inflorescences usually unisexual, rarely with male and female flowers. Male flowers in elongate racemes, rarely solitary; racemes 10-16-flowered, 3 –10(– 30) cm long; peduncles 1.5-12 cm long; bracts ovate, 2-3 mm long, glandular; pedicels of racemose inflorescences 5-20 mm long, of solitary flowers 8-64 mm long; hypanthium broadly campanulate, 2-3 mm long; calyx lobes 5, triangular, 4-10 mm long, puberulous abaxially; corolla lobes 5, ovate–broadly spathulate, 12-20 mm long, ± glabrous, yellow; stamens 3, inserted towards the base of the hypanthium; anthers one 1-thecous, two 2-thecous, flexuose; disc absent. Female flowers: solitary, sometimes paired in axils; pedicels 3 –15(– 20) mm long; ovary ovoid, 8-12 mm long, long-attenuate, pilose, shortly echinate; hypanthium above the constriction and perianth similar to male; staminodes 3; style c. 3 mm long; stigmas 3, 2-lobed, c. 2 mm long. Fruit ovoid, 2.5-4.5 cm long, 2-4 cm diam., glabrescent, echinate, many-seeded, dehiscing by an apical operculum; fruiting pedicel 2 –15(– 20) mm long. Seeds elliptic, 7-8 mm long, 4-5 mm wide, smooth or slightly rugose, dark brown mottled black, the margin narrowly winged.

Representative specimens examined.

AUSTRALIA. Western Australia: Fitzroy River floodplain, river road from Minnie River bridge to Udialla homestead, 27 Apr. 1993, A.A. Mitchell 3040 (CANB); Geikie Gorge, mouth of gorge, 14 May, 1992, I.R. Telford 11721 (CANB); Napier Range, flood plain of Lennard River within Windjana Gorge, 23 Apr. 1988, M.J.S. Sands 4499 (K, L, PERTH); Napier Range, Tunnel Creek, 8 Apr. 1988, C.R. Dunlop 7757 (BRI, DNA); c. 2 km SW of Crystal Heads, A.A. Mitchell 3352 (CANB, PERTH); Mitchell River Falls, Mitchell Plateau, 22 Jan. 1982, K.F. Kenneally 7896 (BRI, PERTH); Lower Ord River, 4 km W of Tarara Bar, 6 July 1994, K.F. Kenneally 11519 (CANB, PERTH); Ord River, C.R. Dunlop, seeds cultivated at Bloomington University, C.B. Heiser 1979 (IU). Northern Territory: Victoria River, 12 km W of Timber Creek, 14 Jul. 1977, J. Must 1630 (BRI, CANB, DNA, NT); Lejeune Station, Barramundi Dam, 21 Feb. 1994, G.J. Leach 4086 (BRI, DNA); Wickham River, J. Russell-Smith 7752 & D.E. Lucas (BRI, CANB, DNA); McArthur River area, sandstone plateau above Glyde River, 17 Feb. 1977, L.A. Craven 3898 (CANB, DNA).

Distribution.

Widespread in the Kimberley, Western Australia and the adjacent north-western Northern Territory, with a disjunction to the McArthur River area of the Northern Territory. Australia’s Virtual Herbarium (http://avh.rbg.vic.gov.au/avh/ accessed 23 March 2011) provides locations for some 50 collections in Australian herbaria, still under the name Luffa graveolens .

Habitat.

Luffa saccata grows in riverine or littoral habitats on sand or clay, sometimes on rocky ridges of limestone or sandstone to 300 m of altitude. Associated species recorded include Eucalyptus camaldulensis , Melaleuca leucadendra and Barringtonia acutangula in gallery forest or woodland, and Eucalyptus miniata , Adansonia gregorii , Brachychiton spp. and Triodia spp. on ridges and littoral Cenchrus grassland.

Phenology.

Flowers and fruits March to October.

Conservation Status.

The species is widespread and common, and we therefore do not consider it at risk. Conserved in Mitchell River and Bungle Bungle Ntional Parks in Western Australia and Gregory National Park in the Northern Territory.

Etymology.

From Latin saccatus, bag-like, obviously in reference to the fruit ( Figs 2 , 3 ).

Notes.

The MEL holotype has two labels in Mueller’s handwriting, one with ' Luffa saccata Baines Creek, May 1856', the other with ' Luffa graveolens , Tributaries of the Victoria River, N.W. Australia, May 1856,' the latter obviously attached after communication with, or reading of, Naudin (1859). It is surprising that Naudin failed to accept Mueller’s Australian Luffa as a good species, since C.B. Clarke (1832-1906), who knew the Indian cucurbits well, made a note on one of the three Kew specimen, saying 'not near [ Luffa ] graveolens which has the males [male flowers] on very short subfasciculate pedicels.' This is indeed one of the differences between the Indian and the Australian species, the latter having the male flowers mostly in elongate racemes. Detailed measurements of living Indian Luffa graveolens plants, black and white photos, and observations on their chromosome numbers are contained in ( Dutt and Roy (1969, 1971).

No material of Luffa graveolens from India is held in the following major herbaria: CGE, E, GH, L, MO, NY, US. This lack of material in western herbaria probably contributed to the Indian and Australian species having been confused for so long. The confusion also affected a recent treatment of Cucurbitaceae in the Flora Malesiana series ( De Wilde and Duyfjes 2010), which states that Luffa aegyptiaca forma sylvestris (Miq.) W.J.de Wilde & Duyfjes is common in Australia (and elsewhere) and comprises "all wild-growing and naturalized small-fruited feral forms" of Luffa . Several Australian specimens of Luffa saccata , such as Sands 4499 ( Fig. 3 ), thus are annotated as Luffa aegyptiaca forma sylvestris. The Luffa specialist C.B. Heiser, on the other hand, cultivated both Australian species, Luffa aegyptiaca and Luffa saccata (under the name Luffa graveolens ), and distinguished them without hesitation ( Heiser and Schilling 1988).

Figures

Figure 2. a Habit of Luffa saccata F. Muell. ex I. Telford b Old fruits. Photos taken near the type locality, Gregory National Park, Northern Territory, by A. Rodd.

Figure 3. Typical herbarium specimens of Luffa saccata: Sands 4499 (L).