Flora of New Zealand Series

orache

Much-branched, prostrate, spreading to suberect, ± farinose annual monoecious herb. Stems ± slender; ribs and nodes often purplish or dark red. Petiole of lower lvs usually 1-2.5 cm long, slender; lamina of lower lvs 1-9 × 0.75-8 cm, mostly narrowly to broadly triangular-hastate, sometimes ± ovate or rhombic-ovate, green, glaucous or sometimes reddish, sparsely to prominently and deeply dentate above basal lobes; base usually truncate, sometimes broad- cuneate or sagittate; apex acute or subacute. Infl. lvs smaller and more often ovate to lanceolate. Infl. of long reddish or brownish spikes; fls in glomerules. ♂ fls: perianth 0.5-0.8 mm long with margins hyaline. ♀ fls: bracteoles 1-2 mm long at anthesis, sessile, triangular-hastate, broad-ovate or rhombic-ovate, usually dentate, less commonly entire, generally with appendages. Fruiting bracteoles to 9 × 6.5 mm, sometimes unequal, almost free or shortly united. Fr. enclosed by bracteoles, 1-2.5 mm long, ± circular, laterally flattened; pericarp easily removed; larger-fruited plants with bracteoles often larger and lacking appendages. Testa shining black or deep brown, smooth.

N.; S.: throughout; St.

Temperate Eurasia, N. Africa 1878

Very common in dune hollows, saline areas especially in C. Otago, also mud flats, coastal stream and shingle banks, and waste places.

FL Dec-Feb.

In some waste places, roadsides and similar modified habitats near the coast plants are generally larger and green rather than glaucous, probably indicating another introduction of the sp. Generally A. prostrata is very variable in habit, colour, lf shape, and bracteole characters; some of this variation seems to be attributable to the degree of exposure to sunlight, salt-laden wind, and drought, and the combination of all 3 often results in quite prostrate, ± succulent plants.

A. novae-zelandiae Aellen was described from the Wellington area; however, there are no characters which allow N.Z. plants of orache or hastate orache to be separated from A. prostrata elsewhere. Aellen's name is therefore placed in synonomy under A. prostrata. The difficulties of defining the members of the A. prostrata group are demonstrated by studies of local populations in Scandinavia [Gustafsson, M., Op. Bot. Lund 39: 3-63 (1976)]. Also for N. America, where it may be introduced, Taschereau, P. M., Canad. J. Bot. 50: 1571-1594 (1972), studied the sp. in Nova Scotia and concluded that it is of little use describing subspecific taxa in A. prostrata because of the plasticity of phenotypes. His findings are also true for N.Z. material. The sp. has been previously known in N.Z. as A. hastata and A. triangularis.

Aellen, P., Bot. Jahrb. 71: 230 (1940), followed by most N.Z. botanists, considered this plant to be indigenous. However, it is probably introduced because it was apparently not collected by early botanists, and this led Cockayne, L. and Allan, H. H., Trans. Roy. Soc. N.Z. 57: 62 (1927, as A. patula), to state that they "regard it as undoubtedly introduced"; it is also not considered indigenous in Australia. Certainly, it was plentiful in some places by the latter half of the nineteenth century. The first indisputable record of this sp. in N.Z. was as A. deltoidea Bab.