Volume II 
JUNE, 1918 
No. 4 
POLLEN PRESENTATION IN CRYPTOSTEMMA 
CALENDULACEUM, R. Br. 
By S. GARSIDE, M.Sc. 
(With one plate.) 
CRYPTOSTEMMA Calendulaceum, R.Br., or Ardotis calendulacea, Willd., 
is a common South African plant, often found abundantly 'as a weed in culti- 
vated areas, and popularly known as “gousblom.” 
On warm, sunny days, during September and October, large patches of 
plants bearing inflorescences, with their bright lemon-yellow coloured ray- 
florets, and greenish-brown disc-florets, may be seen. 
In habit the plant varies considerably. In moist places and on cultivated 
lands, it is much branched and reaches a height of two feet; in arid places it 
is often almost stemless with a rosette of radical leaves and scape-like 
peduncles. 
The disc-florets exhibit a very interesting mode of pollen-presentation, and 
also considerable sensitiveness of the style to contact stimulus, the response 
being a curving of the style in the direction from which the stimulus came. 
These phenomena have been described for closely related species by Minden 1 , 
who described Arctotis aspera, Linn., but gave no figures, and by Small 2 , who 
described the same species more completely and gave figures. 
As both workers made their observations under the artificial conditions 
obtaining in the greenhouse, it was considered that some observations made 
upon a closely allied plant, growing under natural conditions in South Africa, 
would be of interest. 
Pollen presentation in Cryptostemma does not appear to have been pie- 
viously described, as Minden, though he refers to the sensitive styles of this 
plant, confines his detailed account to Arctotis aspera. There is a figure of the 
style of Cryptostemma calendulaceum in the account of the Compositae, by 
Hoffmann, in Die naturlichen PJlanzenf amilien (Engler and Prantl). 
The Cryptostemma inflorescence consists of ray- and disc-florets. 
The ray-florets are ligulate, bright lemon-yellow above, greenish-v e how 
below, and neuter. They are completely devoid of any trace of a style. 1 u 
1 von Minden, 1901. 2 Sma11 ’ 1915 ' 
A. B. H. II. 
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