Cape Province.
Ficoideae. Tribe Mesembryeae.
Mesembryanthemum, Linn.; Benth. et Hook. f. Gen. Plant. vol. i. p. 853.
Mesembryanthemum Pillansii, Kensit in Plant. Nov. Hort. Then. II.
tab. 57 (1908); Botanical Mag. t. 8703.
Dr. R. Marloth supplies the following interesting note on this plant. “Originally found by Mr. Eustace Pillans (not Mr. N. Pillans, as stated in the Botanical Magazine) on the farm Mouton Valley on the Piquetberg mountains to the north-west of Piquetberg.
The present plants were gathered by me at the same locality in October 1922 on sandstone hills among Protea trees (waabom, P. grandiflora), forming shrublets 1½ to 2 ft. high with erect virgate branches.
The description in the Botanical Magazine is fairly correct, but the coloured petals are all radiating on the wild plants (not some erect and conniving, as stated in the Botanical Magazine for the cultivated plants). They are arranged in 5 groups in front of the sepals. The stigmata are distinct and papillate in the later stages of the flower.
The plant is easily cultivated at Cape Town, and I have had it in flower for several years from September to December.
The flowers are of special biological interest. The stamens do not stand erect as in most other species, but are incurved towards the centre to such an extent that the filaments from opposite stamens meet and the anthers are consequently enclosed in the lentil-shaped cavity thus formed above the concave apex of the ovary. The roof of this cavity is further strengthened by the filiform white inner petals which possess a rough surface and are also tightly incurved inwards, meeting at the centre.
The pollen is produced in profusion, and a mass of white powder is found in every flower when slit open at this stage. In all the flowers examined by me I found a number of small black beetles not more than 2 mm. long and a few specimens of haplothrips, all thoroughly covered with pollen. These insects are able to force their way in between the filaments and inner petals, but cannot escape until the stamens wither. Up to that time no stigmatic surfaces are visible in the centre of the flower, but within a few days, when the flower is about a week old and when the pollen at first accumulated in the concave apex of the ovary has been blown away by the wind, the stigmas develop to a length of 2-3 mm., showing a papillate surface, and are then in a condition to be cross-pollinated by the insects released from flowers in the first stage.”