Ants, nectar and a myster 
     
    
   
   
    
     The pttrpose of ectaries itt flowers is 
     
     well known; they nourish insects which. 
     
     in feeding, may effect pollination. Nec- 
     
    
   
   
    
     tarics also occttr on non-flower parts of 
     
     sotne plant species bttt tlte function of 
     
    
   
   
    
     these extrafloral ttectaries (or E.F.N.’s 
     
     for short) is not understood. One 
     
     leading botanist has called tlteir fttnction 
     
     "mysterious". 
     
    
   
   
    
     I knew of the occurrance of I5.I-‘.N.‘s 
     
     on sonte cultivated plants bttt it was not 
     
     until local naturalist Al (‘rrass asked tne 
     
     what I kttew about tltent that I became 
     
     interested in their occurrance in our 
     
     native plants. I scanned the literature. 
     
     fottnd that they occur rather erratically, 
     
     —— in ferns. itt relatives of the confers 
     
     and in the higher flowering plants. 
     
     Studi'es were only beginning to define 
     
     their fttnetion and field observations 
     
     from field naturalists were deetned to be 
     
     needed. 
     
    
   
   
    
     My own interest in E.F.N.'s in our 
     
     native plants is not far advanced; such as 
     
     it is my interest may stimulate other the 
     
     observe. 
     
    
   
   
    
     In our native and domesticated cher- 
     
     ries E.F.N.’s occur on tlte lowest part of 
     
     a leaf stem (petiole); commonly there are 
     
     two, one on each side of the petiole. just 
     
     below the leaf blade; however their 
     
     number. shape and size varies frotn loca- 
     
     tion to location itt our Province. It may 
     
     well be that the amount and nature of 
     
     the nectar they produce varies also. It is 
     
     now documented that sugars are only 
     
     one class of many compounds found in 
     
     nectar. 
     
    
   
   
    
     Chokecherry (Prmms demissu), corn- 
     
     tnon itt the drier parts of B.C., has well 
     
     developed E.F.N.’s; the E.F.N.‘s of bit- 
     
     ter cherry (P. entergima), which is found 
     
     more widely in somewhat more humid 
     
     environtnents, are small and are often 
     
     reduced to mere pits. Barbara Bentley, 
     
     who has studied E.F.N.'s of many 
     
     species in several parts of the world, 
     
     finds that ants make use of the E.F.N.‘s 
     
     nectar and that itt doing so repel other 
     
     insects which might devour the all im- 
     
     portant green leaf; plants and ants have 
     
     developed a relationship of benefit to 
     
     both. Ther‘ are now some experiment 
     
     with cultivated plants e.g. cotton where 
     
     if E.F.N.’s and/or ants are removed 
     
     substantially reduced harvests result. I 
     
     common observe ants feeding from 
     
     chokechcrry L’.I~'.N.‘s but not very often 
     
     from those of bitter cherry. 
     
    
   
   
    
     ls plant-ant tnutualism the only 
     
     system in which E.F.N.‘s: to name but a 
     
    
   
   
    
       
     
    
   
   
    
     ' 4‘"  
     
     Extra 
     
     ehokeeherry (I’runus demissa) 
     
    
   
   
    
     few-bracken fern, willow, poplar, smart- 
     
     wecd, lousewort. Ants on many of these 
     
     do not scent to be very common or are 
     
     absent. ()ne group of plants with 
     
     E.I7.N.'s in which I have been interested 
     
     are the jewclwecds (also known as 
     
     touch-me-not, or policetnan's helmets) 
     
     (IIIUHII/UIM‘Ali/1.). ’l ltey normally grow itt 
     
     damp shady habitats where ants are few 
     
     or absent; their [3.I".N.‘s are prominent 
     
     and usually clustered below the flowers 
     
     and developing fruits. l have observed 
     
     most closely I. g/undu/t'fera (presumed to 
     
     be an introduction front Asia) and I. 
     
     ec‘ulearala. I cannot state that I ltave 
     
     never seen ants in their vicinity but they 
     
     are rare; on the other hand I have seen 
     
     aphids and a few other insects using the 
     
     nectar. Could it be that the E.F.N.‘s are 
     
     a lure to keep predators front the 
     
     reproductive structures? Many nectars 
     
     contain constituents which may be nar— 
     
     cotic or toxic. Perhaps these are present 
     
    
   
   
    
     :, V“. . .,  
     
    

    
     * @gfifixa 
     
     i“  "’"’_‘ n 
     
     .fifi3gggfi. 
     
    
   
   
    
     l neetaries can be seen as small structures on the petiole of the leaf of 
     
    
   
   
    
     in the Impatiens net'tar? There are lots 
     
     of examples of nectats which are nar- 
     
     cotic. Maybe in some species such as a 
     
     bitter cherry, where Ii.I-‘.N.'s are very 
     
     small, they are in the process of becom- 
     
     ing, useless or vestigcal because they are 
     
     few ptcynaciotts ants iii the habitats to 
     
     which the bitter cherry has become 
     
     adapted? Questions then remain about 
     
     E.F.N. function which, maybe field 
     
     observations by B.C. naturalists could 
     
     help to answer? 
     
    
   
   
    
     1. THE BIOLOGY OF NEC- 
     
     TARINES. B. Bentley, and T. Elias, 
     
    
   
   
    
     editors. Columbia University Press 
     
     (I983). 
     
    

    
     2. EXTRAFLORAL NECTARIES 
     
     AND PROTECTION BY 
     
    
   
   
    
     PUGNACEOUS BODYGUARDS. I3. 
     
     Bentley. Ann. Rev. Ecolo. and Systems 
     
     8:427 (I977). 
     
    

    
     V. C. Brink 
     
    
   
   
    
     (reprinted from the December I986 issue of the 
     
    
   
   
    
     B.C Naturalist) 
     
    
   
   
    
     AND JUST A FEW BIRD SIGHTINGS FOR THIS ISSUE!! 
     
    
   
   
    
     Geoff Hogan saw a cuckoo Sp. 
     
    
   
   
    
     on Oct. 6. On Oct. 
     
    
   
   
    
     in Dunstaffnage 
     
    
   
   
    
     10, Dan McAskill saw two 
     
     mature and one immature red—tailed hawk, 
     
    
   
   
    
     and 
     
    
   
   
    
     one rough-legged hawk (dark phase) in Irish- 
     
    
   
   
    
     town . 
     
    
   
   
    
     _ 11 _