Pigott. — Notes on Nothopanax arboreum. 601 



Inflorescence. 



The inflorescence of Nothopanax arboreum is composed of compound 

 umbels, three times divided. These spring from the tips of the branches, 

 and are shorter than the leaves. Quite often two peduncles spring laterally 

 from below the origin of the others. The number of branches in each umbel 

 is very irregular — the primary peduncles numbering from twelve to fifteen, 

 the secondary branches from fifteen to thirty, and the actual flower-pedicels 

 from five to fifteen. Though very irregular in number, these stalks are 

 very uniform in length. In some of the male trees examined the peduncles 

 and pedicels were much flattened. 



Male Tree. 



The plant is dioecious, male trees bearing brown rounded buds with five 

 microscopic sepals, five petals, five stamens, and a gynoecium with two 

 carpels and two style-arms. The petals, which are valvate in the bud, 

 are brown on the outer surface and greenish-brown on the inner, small, and 

 pointed. The stamens have large anthers packed upright in the buds, and 

 there are corresponding depressions in the disc to accommodate their bases. 

 They alternate with the petals. The style-arms are two, upright in the bud, 

 small and thick, which diverge when the flower opens. The buds are pro- 

 tected in the young stage by masses of colourless mucilage, which later 

 falls away. This is said to arise from hairs which are developed with the 

 flower-buds. In about three months (April-June) from their first appear- 

 ance the buds open. The petals expand like a star, the filaments of the 

 stamens lengthen considerably till about as long as the petals, and the 

 stigmas diverge somewhat. They possess a red colour, which was also seen 

 while in the bud. 



Pollination. 



The flower soon becomes distinctly scented, and small quantities of 

 nectar are seen on the disc. They are then visited by blow-flies, and very 

 occasionally by bees. The latter, however, on account of the length of the 

 proboscis, cannot make use of the nectar. A short time after the opening 

 of the flower the ovaries become compressed, and often much deformed. 

 When all the pollen is shed, an absciss layer is formed at the base of the 

 receptacle, and the flower is cast off. Later the pedicels and peduncles 

 are also cut off. The ground below male trees becomes strewn with flowers, 

 especially after rain. 



On one male tree examined there was found an umbel of seven well- 

 formed fleshy fruits, with two seeds each. Also, later in the season 

 (September), when the crop of male flowers had all fallen, an inflorescence 

 of hermaphrodite buds was found on the same tree. 



Compression of the receptacle is accompanied by a swelling in the ovary- 

 wall, but the ovule itself withers before the flower falls. 



Female Trees. 



On female trees the buds are compressed from very early stages, and 

 consist of an enlarged receptacle enclosing the ovary and a small perianth- 

 cap consisting of five microscopic sepals, five petals (smaller than those 

 of the male plant), usually five staminodes (though it is not uncommon to 

 find that there are four or only three formed) . These staminodes have very 



