NOTES AND ABSTRACTS. 167 



Oranges, Mandarin, Pear-shaped. By J. Burin {Rev. Hort. de 

 VAlg. July 1913, p. 270). — It is sometimes supposed that the pear- 

 shaped mandarins which come into the market are the produce of 

 a distinct variety of Citrus. This has, however, been proved not to 

 be the case. The pecuHarity is never transmitted by grafting, and 

 may be produced at any time, as the result of extra irrigation and 

 of excessive appHcations of manure, especially if this is nitrogenous. 



M. L. H. 



Onion Seed Growing, 'Denia.' By Fabian Garcia {U.S.A. Exp. 

 Stn., New Mex., Bull. 82 ; March 1912 ; plates). — An account of some 

 experiments in raising the Spanish onion in New Mexico. So far 

 the Spanish or Denia onion has not been grown on a commercial 

 scale in the United States. It has been proved, however, that this 

 onion will grow and thrive and ripen seed in many localities in New 

 Mexico, and the quality of the home-grown ' Denia ' onion seed is fully 

 equal to that of imported seed, the price of which is almost prohibitive 

 to the American farmer. — M. L. H. 



Orchid, An, with Explosive Flowers. — Dr. H. N. Ridley {Straits 

 Settlements Gard. Bull. vol. i. 1913, pp. 191-3) describes an 

 orchid from Sarawak which shows a remarkable floral mechanism. 

 This species {Plocoglottis porphyrophylla) is widely distributed in 

 Malaya, but, being inconspicuous and a lover of deep shade, is but little 

 known. It bears only one flower open at a time, but remains in flower 

 for over three months, producing a fresh flower every few days until 

 the raceme is more than two feet long and has borne about fifty flowers. 

 In the young flower the ovary begins to twist, as usual in orchids, 

 until it has overtopped the bract ; it carries the swelling bud through 

 about 75 degrees and then stops twisting. During this twisting the 

 dorsal sepal outgrows the other two sepals and pushes over the apex 

 of the bud. All the sepals at this stage are similarly narrowly ovate, 

 the lateral ones asymmetrically so. The lateral petals are linear and 

 curved round the column to meet at their tips. The lip is about as 

 broad as long, cuspidate above its broad shoulders, with the margins 

 in the lower part frilled and turned under ; if these margins are un- 

 curved it is seen that they are the lateral lobes of the lip. Under 

 each broad shoulder a wart has begun to form. Between this stage 

 of the bud and maturity the following changes occur : The contiguous 

 halves of the lateral sepals thicken from the middle upwards ; the 

 cuspidate tip of the lip turns back, its shoulders enlarge and the warts 

 become sharp little upstanding cones, while the side lobes increase 

 along their margins so that they are too full for the space they have, 

 and towards the base of the lip tend to form an upstanding rounded 

 crest ; two very fleshy staminodes lie within the curve of this crest, 

 one on each side. In opening, which occurs in late afternoon or early 

 evening, a sht appears between the lateral sepals, then these sepals 

 break away and slowly take up a position at right angles to the ovary. 



