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A NEW MIMICRY PLANT. 
(Mesembrianthemum lapidiforme, Marl.) 
By R. Marloth. 
(Received and Read October 16, 1913.) 
The species reserobles in the shape of its leaves M. Bolusii, but the 
flowers are quite different, and, as a matter of fact, unique in their mode 
of insertion and attachment. During the dry season (November-March) 
the plant consists merely of one pair of leaves, each one shaped like a 
tetrahedron, with rounded edges and points, the two bodies being pressed 
against each other with their bases. In nature these leaves are of a 
brownish-red colour and closely resemble the angular pieces of brown 
shale and sandstone between which the plants grow. As they are half- 
buried in the ground they can be detected only with difficulty, even in 
localities where their occurrence is known. 
In winter, when rain has fallen, a new pair of leaves appears between 
the old ones, forcing them apart, and in spring two opposite flowers 
are produced from the central axis just outside the junction of the old 
leaves, not between them as in M. Bolusii and other members of the 
section Aloidea. These flowers are peduncled, the peduncles bearing 
two fleshy bracts near their base. The connection between the base 
of the peduncle and the plant is very thin, about J mm. only. This is 
obviously an adaptation to the dispersal of the ripe seed-vessel, which 
becomes easily detached at this spot, to be carried away by the wind. 
At that time (beginning of summer) the old leaves have shrivelled up, 
the new pair has assumed the colour of the surrounding stones, and the 
plant remains dormant until the winter brings rain again. 
Mesembrianthemum lapidiforme, spec. nov. (Sect. Aloidea). 
Planta acaulis. Folia 2-4, crassa, brevissima, triquetra, subtus plano- 
convexa, superne obtuso-carinata apice obtusissimo. Flores 2, laterales, 
oppositi, pedunculati, bibracteati. Sepala 6 ; petala linearia, alba, sepalis 
longiora. Stigmata 6. 
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