Joycea H.P. Linder
Named in honour of Joyce Vickery, a very productive agostologist from Sydney.
Sometimes referred to Chionochloa, Danthonia sensu lato, Notodanthonia, Rytidosperma
Habit, vegetative morphology. Perennial; rhizomatous, or caespitose. The flowering culms leafless. Culms 25–160 cm high; cylindrical; unbranched above; 2–4 noded. Culm nodes exposed; glabrous. Culm internodes solid. Young shoots intravaginal. Leaves mostly basal; non-auriculate; without auricular setae. Leaf blades linear-lanceolate; neither leathery nor flimsy; narrow; 3–20 mm wide; flat; without abaxial multicellular glands; without cross venation; persistent; a fringe of hairs; not truncate. Contra-ligule absent.
Reproductive organization. Plants bisexual, with bisexual spikelets; with hermaphrodite florets. The spikelets all alike in sexuality; hermaphrodite.
Inflorescence. Inflorescence many spikeleted; paniculate; open; more or less irregular; non-digitate; espatheate. Spikelet-bearing axes persistent. Spikelets solitary; not secund; not two-ranked; pedicellate; not imbricate; not in distinct ‘long-and-short’ combinations.
Female-fertile spikelets. Spikelets morphologically ‘conventional’; 9–25 mm long; cuneate; green to purplish; compressed laterally; disarticulating above the glumes; disarticulating between the florets; with conventional internode spacings. The upper floret not stipitate. Rachilla prolonged beyond the uppermost female-fertile floret; hairless; the rachilla extension with incomplete florets. Hairy callus present. The callus hairs white. Callus short (slightly shorter than the rhachilla); blunt.
Glumes two; more or less equal; about equalling the spikelets; long relative to the adjacent lemmas; hairless; scabrous; pointed; not subulate; awnless; carinate; without a median keel-wing; similar. Lower glume much exceeding the lowest lemma; relatively smooth; 1–7 nerved. Upper glume 1–7 nerved. Spikelets with incomplete florets. The incomplete florets distal to the female-fertile florets. The distal incomplete florets merely underdeveloped; awnless. Spikelets without proximal incomplete florets.
Female-fertile florets 3–6. Lemmas deeply bilobed, the lobes tapering into apical setae; not convolute; not saccate; similar in texture to the glumes; smooth, or striate; not becoming indurated; white in fruit; incised; 2 lobed; deeply cleft; awned. Awns 1, or 3; if solitary median, or median and lateral (if three); if three different in form from the laterals; from a sinus; geniculate; hairless; much longer than the body of the lemma; entered by several veins; persistent. Awn bases twisted; flattened. Lemmas hairy (scattered on the lower half of the lemma backs). The hairs not in tufts (or scarcely so); not in transverse rows. Lemmas non-carinate; without a germination flap; 9 nerved; with the nerves confluent towards the tip. Palea present; relatively long; not convolute; tightly clasped by the lemma; apically notched; awnless, without apical setae; thinner than the lemma; not indurated; 2-nerved; 2-keeled. Palea back glabrous, or hairy. Palea keels wingless; scabrous, or hairy. Lodicules present; 2; free; fleshy; ciliate; not or scarcely vascularized. Stamens 3. Anthers 1.2–5.2 mm long. Ovary glabrous. Styles free to their bases; free. Style bases widely separated. Stigmas 2; red pigmented.
Fruit, embryo and seedling. Disseminule a caryopsis enclosed in but free of the lemma and palea. Fruit free from both lemma and palea; small; brown; fusiform (obovate); not grooved; compressed dorsiventrally; glabrous; smooth. Hilum short (linear to ovate, almost half as long as fruit). Pericarp thin; fused. Embryo large; waisted.
Ovule, embryology. Micropyle not noticeably oblique. Outer integument more than two cells thick at the micropylar margin. Inner integument discontinuous distally; not thickened around the micropyle. Synergids haustorial (strongly developed); exhibiting large, globular starch grains.
Transverse section of leaf blade, physiology. C3; XyMS+. Sclerenchyma all associated with vascular bundles (J. pallida).
Cytology. Chromosome base number, x = 6. 2n = 12. 4 ploid, or 6 ploid, or 8 ploid.
Taxonomy. Arundinoideae; Danthonieae.
Distribution, ecology, phytogeography. 3 species; Australia. Not commonly adventive. Mesophytic; species of open habitats (light shade); glycophytic. Gravelly soils.
Australian. North and East Australian.
References, etc. Morphological/taxonomic: This description prepared by H.P. Linder (1997).
Illustrations. • Abaxial epidermis of leaf blade. • Abaxial epidermis of leaf blade. Joycea pallida. • Transverse section of leaf blade. Joycea pallida. • Transverse section of leaf blade. Joycea pallida
Cite this publication as: Watson, L., and Dallwitz, M. J. (1992 onwards). ‘Grass Genera of the World: Descriptions, Illustrations, Identification, and Information Retrieval; including Synonyms, Morphology, Anatomy, Physiology, Phytochemistry, Cytology, Classification, Pathogens, World and Local Distribution, and References.’ http://biodiversity.uno.edu/delta/. Version: 18th August 1999. Dallwitz (1980), Dallwitz, Paine and Zurcher (1993 onwards, 1998), and Watson and Dallwitz (1994), and Watson, Dallwitz, and Johnston (1986) should also be cited (see References).
