361 PLANTS STERILE WITHOUT INSECT-AID. Chap. X. 



Vcrbascumphceniceum (Scrophulariacese). Quite sterile! s^my ^ac. 



V. nigrum. Quite sterile ..... ) sterile plants. 



Campanula carpaihica (Lobeliaceae). Quite sterile. 



Lobelia ramosa (Lobeliacesa). Quite sterile. 



L.fulgens This plant is never visited in my garden by bees, 

 and is quite sterile ; but in a nursery-garden at a few miles' 

 distance I saw humble-bees visiting the flowers, and they 

 produced some capsules. 



Isotoma (a white-flowered var.) (LobeliaceEe). Five plants left 

 unprotected in my greenhouse produced twenty-four fine 

 capsules, containing altogether 12 '2 grains weight of seed, 

 and thirteen other very poor capsules, which were rejected. 

 Five plants protected from insects, but otherwise exposed 

 to the same conditions as the above plants, produced sixteen 

 fine capsules, and twenty other very poor and rejected ones. 

 The sixteen fine capsules contained seeds by weight in such 

 proportion that twenty-four would have yielded 4*66 

 grains. So that the unprotected plants produced nearly 

 thrice as many seeds by weight as the protected plants. 



Leschenaultia formosa (Goodeniacese). Quite sterile. My experi- 

 ments on this plant, showing the necessity of insect aid, 

 are given in the * Gardeners' Chronicle,' 1871, p. 1166. 



Senecio cruentus (Compositae). Quite sterile : see my account of 

 self-sterile plants. 



Ihterocentron mexicanum (Melastomacese). Quite sterile; but 

 this species and the following members of the group pro- 

 duce plenty of seed when artificially self-fertilised. 



PJiexia glandulosa (Melastomaceae). Set spontaneously only two 

 or three capsules. 



Ceniradenia floribunda (llelastomacess). During some years pro- 

 duced spontaneously two or throe capsules, sometimes 

 none. 



rieroma (unnamed species from Kew) (Melastomaceae). During 

 some years produced spontaneously two or three capsules, 

 sometimes none. 



Monochcetum e^/eram (Melastomaceae). During some years pro- 

 duced spontaneously two or three capsules, sometimes 



none. 



Hedychium (unnamed species) (Marantacese). Almost self-sterile 



without aid. 

 Orchidece. An immense proportion of the species sterile, if 

 insects are excluded. 



