. Dansk botanisk arkiv. Plants; Plants -- Denmark. Fig 19. Posidonia australis. Diagram of an inflorescence. sclerenchyma-strands at the points where the septa between the lacunæ (air-chambers) meet. (The structure of some doubtful Posidonia-ledives is dealt with later, p. 37). The inflorescence is terminal on a long naked axis. It is distichous and branching, and consists of about three branch- spikes and the terminal spike; these are supported by and en- veloped in bracts with large sheaths, the leaf-blade being short or absent. A diagram (Fig. 19) of an inflorescence shows the arrangement o
. Dansk botanisk arkiv. Plants; Plants -- Denmark. Fig 19. Posidonia australis. Diagram of an inflorescence. sclerenchyma-strands at the points where the septa between the lacunæ (air-chambers) meet. (The structure of some doubtful Posidonia-ledives is dealt with later, p. 37). The inflorescence is terminal on a long naked axis. It is distichous and branching, and consists of about three branch- spikes and the terminal spike; these are supported by and en- veloped in bracts with large sheaths, the leaf-blade being short or absent. A diagram (Fig. 19) of an inflorescence shows the arrangement of the bracts and spikes. The lowermost bract has a blade longer than the sheath, while the blades become gradually reduced in size in passing up the inflorescence. The two lowermost lateral spikes are more or less long-stalked, and their bracts are placed towards the upper end of the axis, while the uppermost lateral spike has its bracts nearly in the axil of the supporting bract of the main axis. All the lateral spikes begin with a short bladeless prophyllum in the axil between the main axis and the branch. The number of bracts immediately supporting the spikes varies from two to four. Each spike bears 4—6 (perhaps sometimes more) flowers placed at some distance from each other; the axis is continued into a horn-like process above the uppermost flower (which consequently is lateral like the other ones). In Posidonia oceanica it is stated that the uppermost flower of each spike is male while the others are hermaphrodite. I have not had flowering material of P. australis at my dis- posal, but to judge from the fruiting specimens Fig 20 Posidonia au. all the flowers seem to be hermaphrodite in $tralis,iromGera]dton. . _,. _m . • +i A lateral fruiting spik- this species (see Fig. 20). There is no perianth. elet (Nat sizef The broad connectives of the three sessile anthers are persistent on the fruit. Their shape is somewhat var- iable, being shorter or longer ovate-lanceolate
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