ORCUTTIA 



47 



(10 Brit., incl. O. mascula L., early purple orchis, and O. maculata 

 L , spotted orcliis.) Sympodial perennials forming one tuber each 

 year (see fam.). The fls. stand in a dense spike and have curious 

 mech. for insect fert. The anther is basitonic and well above the 

 stigmas. The rostellum has an outer firm pouch, inside which is the 

 viscid substance to which are firmly attached the caudicles of the 

 pollinia. An insect entering the fl. probes the spur of the labellum 

 and its back comes into contact with the rostellum and depresses the 

 pouch, causing the viscid substance to adhere to the insect. The 

 tissue of the spur has to be drilled for honey, and while this is being 

 done the cement rapidly sets, so that, as the insect leaves the fl., it 

 takes with it the pollinia, standing upright on their caudicles. If 

 they remained in this position they would never touch the stigmas of 

 another fl., but as soon as the caudicles are exposed to air, they con- 

 tract on the side towards the base of the fl. (i.e. towards the insect's 

 head) and move the pollinia downwards from ! to . In this position, 

 when the insect enters another fl., they pass under the rostellum and 

 strike the stigmas. [See Darwin's Orchids for details.] 

 Orchis, Orchis, any terrestrial member of Orchidaceae ; bee-, Ophrys 

 apifera Huds. ; bird's nest-, Neottia; butterfly-, Habenaria, On- 

 cidiuni ; dove-, Peristeria; early purple -, O> r/u's mascula L.; fly-, 

 Ophrys mitscifera Huds.; frog-, Habenaria (Coeloglossum) viridis 

 R. Br.; lady's slipper-, Cypripedium ; man-, Aceras anthropophora 

 R. Br.; musk -, Herminium Monorclns R. Br.; scented-, Gymna- 

 denia conopsea R. Br.; spider-, Ophrys aranifera Huds.; spotted-, 

 Orchis maculata L. 



A D. Orchis mascula (Purple Orchis). A. Front view of anther and top of 

 column ; a, anther ; s, s, pair of stigmatic surfaces, one on each side of the 

 rostellum, r. The pollen-sacs have split lengthwise, exposing the pollinia in the 

 upper portion. On either side of the anther is a blunt outgrowth representing a 

 sterile stamen. B. Dissection of flower, side view, showing part of lip and the 

 spur (s/>) and the relation of rostellum (>-) and stigma (s) to entrance of spur. 

 C. Base of pair of pollinia, front view ; c, caudicles ; r, rostellum ; g, gland ; 

 i, membranous disc. D. Single pollinium, the pollen-containing portion 

 separated, showing arrangement of packets of pollen on the two main axes. 



E. Pollinia of O. pyramidalis attached to a common gland (jr). 



All enlarged. A, D, from original drawing by Fr. Bauer. B, C, E, after Darwin. 



Orchiserapias x E. G. Camus. Orchidaceae. Hybrid, Orchis-Serapias. 

 Orcuttia Vasey. Gramineae (10). i California. 



