COMMELINIDAE Takht.

Takhtajan, Sist. Filog. Cvetk. Rast. [Syst. Phylog. Magnolioph.]: 514. 4 Feb 1967


[Arecaceae+Dasypogonaceae+[Commelinanae+Cyperales]]


DASYPOGONACEAE Dumort.

Dumortier, Anal. Fam. Plant.: 54, 55. 1829 [’Dasypogoneae’]

Calectasiaceae Endl. ex Schnizlein, Iconogr. Fam. Regn. Veg. 1: 51******. Jan-Jul 1845 [’Calectasieae’]; Kingiaceae Endl. ex Schnizlein, Iconogr. Fam. Regn. Veg. 1: 51*****. Jan-Jul 1845; Baxteriaceae Takht. in Bot. Žurn. 81(2): 85. Mai-Jun 1996; Dasypogonales Reveal ex Doweld, Tent. Syst. Plant. Vasc.: lxi. 23 Dec 2001

Genera/species 4/16

Distribution Southwestern Australia; one species of Calectasia in Victoria.

Fossils Unknown.

Habit Bisexual, usually perennial herbs (in Kingia often with woody trunk and with numerous adventitious roots, penetrating leaf bases and covering large parts of stem). More or less xeromorphic. Some species have stilt roots. Baxteria lacks a supraterranean stem.

Vegetative anatomy Mycorrhiza absent. Phellogen? Primary vascular tissue in the form of scattered bundles. Primary lateral growth sometimes considerable (Dasypogon, Kingia). Secondary lateral growth absent. Vessels present in roots only. Vessel elements with scalariform (Baxteria, Kingia) or simple (Calectasia, Dasypogon) perforation plates; lateral pits? Imperforate tracheary xylem elements tracheids. Wood rays? Axial parenchyma? Two peripheral phloem strands in foliar bundles (Baxteria and Kingia with both phloem fibres and thin-walled fibres in outer bundle envelopes; Baxteria with sclerenchyma girdles formed within mesophyll reaching from outer bundle envelope cells to epidermis). Sieve tube plastids P2c type, with cuneate protein crystals, without starch or protein filaments. Nodes multilacunar with several leaf traces. Calciumoxalate raphides present in flowers of Calectasia and Dasypogon. Silica bodies present.

Trichomes Hairs multicellular, uniseriate or multiseriate, or absent.

Leaves Alternate (spiral), simple, entire, with ? ptyxis. Stipules absent; leaf sheath well developed. Leaf bases long persistent. Two peripheral phloem strands present in foliar vascular bundles. Venation parallelodromous. Stomata paracytic or tetracytic (Baxteria, Kingia) or of unique type with several subsidiary cells (Calectasia, Dasypogon). Cuticular wax crystalloids non-orientated. Epidermal cells usually with silica crystals as druse-shaped accumulation; in Calectasia and Dasypogon also with silica sand or amorphous silica crystals. Mesophyll sometimes with calciumoxalate crystals. Leaf margin usually entire (sometimes finely serrate).

Inflorescence Terminal, capitate (Dasypogon, Kingia) or flowers solitary (Baxteria, Calectasia).

Flowers Actinomorphic, in Baxteria large. Hypogyny. Tepals 3+3, parchment-like to petaloid, dry or fleshy, persistent, free (Baxteria, Kingia), or entirely or partially connate (Calectasia, in Dasypogon only outer tepals largely connate). Septal nectaries in Dasypogon and Kingia as pits at base of gynoecium. Disc absent.

Androecium Stamens 3+3. Filaments free, usually adnate to tepals (epitepalous). Anthers usually basifixed (in Dasypogon dorsifixed), non-versatile?, tetrasporangiate, introrse, longicidal (usually dehiscing by longitudinal slits; in Calectasia poricidal, dehiscing by two apical pores or short slits). Tapetum? Staminodia absent.

Pollen grains Microsporogenesis successive. Pollen grains monosulcate (in Baxteria unique pollen type with surface subdivided into separate parts consisting of repeatedly branched colpus, colpus membrane formed of coarse pieces with principally similar surface pattern as mesocolpia [intercolpial surfaces]), shed as monads, ?-cellular at dispersal. Pollen grains without starch. Exine tectate, with columellate? infratectum, microreticulate or punctate (in Kingia psilate).

Gynoecium Pistil composed of three connate carpels. Ovary superior, unilocular (Calectasia) or trilocular. Style single, simple, long, narrow, with stylar canal. Stigma trilobate (Baxteria) or capitate, Wet type? Pistillodium absent.

Ovules Placentation usually axile (in Calectasia basal). Ovules usually one (rarely two) per carpel, anatropous, ascending, epitropous?, bitegmic, crassinucellar. Micropyle bistomal, Z-shaped (zig-zag). Outer integument six to eight cell layers thick. Inner integument two? cell layers thick. Nucellar cap approx. two cell layers thick. Parietal tissue approx. two cell layers thick. Megagametophyte monosporous, Polygonum type, usually small. Synergids with a filiform apparatus? Chalazosperm large, subdermal, starchy, without central axially orientated cells. Endosperm development ab initio nuclear. Endosperm haustoria? Embryogenesis?

Fruit Usually nutlike, indehiscent, enclosed by persistent perianth; in Baxteria a septifragal explosively dehiscing capsule: each valve split into two halves, inner wall of each valve forming plate kept under tension and finally springing upwards dispersing seed.

Seeds Aril absent. Testa light yellow (phytomelan absent), in Calectasia membranous. Outer epidermis with pitted thick-walled cells storing fat, aleurone and hemicellulose. Tegmen? Perisperm not developed. Endosperm copious, without starch (Dasypogon). Embryo lens-shaped, short, wide, well differentiated, chlorophyll? Cotyledon one. Cotyledon hyperphyll? Hypocotyl internode absent. Mesocotyl present in Dasypogon. Coleoptile present? Germination?

Cytology x = 7 (Baxteria, Dasypogon, Kingia), 9 (Calectasia) – In Calectasia the chromosome nine has mutated, most of the genetic material being inherited as one large supergene, i.e. permanently conserved heterozygosity.

DNA

Phytochemistry Insufficiently known. Ferulic acid (in cell walls) and chelidonic acid (in Dasypogon bromeliifolius) present. Flavonols, ellagic acid, proanthocyanidins, and cyanogenic compounds not found.

Use Ornamental plants.

Systematics Dasypogonaceae consist of two main clades (Rudall & Chase 1996), Dasypogoneae and Kingieae. A weakly supported sister-group relationship between Dasypogonaceae and Arecaceae was identified by Barrett & al. (2013).

Dasypogoneae Engl. in Engler et Prantl, Nat. Pflanzenfam. II, 5: 18. 26 Mar 1887

2/14. Dasypogon (3; southwestern Western Australia), Calectasia (11; southwestern Western Australia, Victoria). – Southwestern Australia, Victoria. Vessels with simple perforation plates. Raphides present only in floral parts. Hairs branched. Foliar vascular bundles without girdles. Stomata of unique type with several subsidiary cells and aberrant ontogeny of subsidiary cells. Epidermis with silica. Inflorescence capitate; flowers in groups or solitary. Tepals more or less connate into a short tube. Stamens adnate to base of perianth tube. Megasporangium massive, nutrient-storing (present below megagametophyte). Fruit indehiscent. Tegmen collapsing. Cotyledon not photosynthesizing. Mesocotyl and coleoptile present. n = 7, 9. Chelidonic acid present in Dasypogon.

Kingieae Horan., Char. Ess. Fam.: 39. 17 Jun 1847

2/2. Kingia (1; southwestern Western Australia), Baxteria (1; southwesternmost Western Australia). – Southwestern Australia. Kingia with monopodial growth, retarded apical meristem (similar to Arecaceae), and with epicortical adventitious roots growing downwards inside persistent sheathing stem-enclosing leaf bases. Vessels with scalariform perforation plates. Raphides absent. Foliar vascular bundles with girdles formed in mesophyll. Stomata paracytic or tetracytic. Inflorescence capitate (Kingia) or one-flowered (Baxteria), surrounded by bracts. Peduncle (scape) bracteate. Tepals free. Filaments adnate to tepal bases. Pollen grains extended sulcate-unipantocolpate. Fruit indehiscent (Kingia) or explosively septifragal (Baxteria). n = 7.

Cladogram of Dasypogonaceae based on DNA sequence data (Rudall & Chase 1996).


Literature

Anway JC. 1969. The evolution and taxonomy of Calectasia cyanea R. Br. (Xanthorrhoeaceae) in terms of its present-day variation and cytogenetics. – Aust. J. Bot. 17: 147-159.

Barrett RL, Dixon KW. 2001. A revision of the genus Calectasia (Calectasiaceae) with eight new species described from South-West Western Australia. – Nuytsia 13: 411-448.

Bedford DJ, Lee AT, Macfarlane TD, Henderson RJF, George AS. 1986. Xanthorrhoeaceae. – In: George AS (ed), Flora of Australia 46, Australian Government Publ. Service, Canberra, pp. 88-171.

Chanda S, Ghosh K. 1976. Pollen morphology and its evolutionary significance in Xanthorrhoeaceae. – In: Ferguson JK, Muller J (eds), The evolutionary significance of the exine, Linn. Soc. Symposium, No. 1, Academic Press, London, New York, pp. 527-559.

Clifford HT, Keighery GJ, Conran JG. 1998. Dasypogonaceae. – In: Kubitzki K (ed), The families and genera of vascular plants IV. Flowering plants. Monocotyledons. Alismatanae and Commelinanae (except Gramineae), Springer, Berlin, Heidelberg, New York, pp. 190-194.

Fahn A. 1954. The anatomical structure of the Xanthorrhoeaceae Dumort. – Bot. J. Linn. Soc. 55: 158-184.

Fahn A. 1961. The anatomical structure of the Xanthorrhoeaceae Dumort. and its taxonomic position. – In: Recent advances in botany 1, Toronto, pp. 155-160.

Keighery GJ. 1983. Ballistochory (explosive seed dispersal) in Baxteria R. Br. (Xanthorrhoeaceae). – W. Aust. Nat. 15: 163-166.

Keighery GJ. 1984. Chromosome numbers of Australian Liliaceae. – Feddes Repert. 95: 523-532.

Krause K. 1930. Liliaceae. – In: Engler A (ed), Die natürlichen Pflanzenfamilien, 2. Aufl., Bd. 15a, W. Engelmann, Leipzig, pp. 227-386.

Neyland R. 2002. A phylogeny inferred from large-subunit (26S) ribosomal DNA sequences suggests that the family Dasypogonaceae is closely aligned with the Restionaceae allies. – Aust. Syst. Bot. 15: 749-754.

Rudall PJ. 1994. The ovule and embryo sac in Xanthorroeaceae sensu lato. – Flora 189: 335-351.

Rudall PJ, Chase MW. 1996. Systematics of Xanthorrhoeaceae sensu lato: evidence for polyphyly. – Telopea 6: 185-203.

Shapcott A, Bau B, Katik P. 2008. The potential implications of rainforest history, hybridization, and climate change on the phylogenetics of a rare genus of herbs Romnalda (Dasypogonaceae) from New Guinea and Australia. – Bot. J. Linn. Soc. 157: 455-474.