426 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



devotes a chapter to it. In north-west Middlesex this species is remark- 

 ably variable in colour, so much so that we have it at Stanmore with 

 flowers ranging from almost pure white to pale purple, and a more 

 interesting batch of plants cannot be imagined than these, when they 

 Mower in June. 



Flowering about the same time and in the same soil is Orchis Morio 

 (the Green-winged Orchis), an Orchid that is sometimes mistaken for 

 0. mascula when not in flower. When, however, in flower there can be 

 no mistake, as the spreading and sometimes reflexed lateral sepals of 

 0. mascula differentiate it distinctly from the hood-like and arching 

 sepals of 0. Morio. 



Another Orchid with green or greenish flowers is the Tway Blade 

 (Listcra ovata). In such a bed as I have described this plant will grow 

 in the stiff loam, and if the flowers are not particularly attractive there is 

 a quaintness about a finely developed spike that appeals to all flower 

 lovers, and then its contrivances for pollination are simply wonderful, and 

 flowering in one's garden it enhances considerably the value of that 

 wonderful classic, Darwin's " Fertilisation of Orchids," since so large 

 a part of it is devoted to the interpretation of this modest little plant. 



One other Orchid I specially recommend 0 for the loam bed — the 

 Butterfly Orchis {Habcnaria bifolia), a very beautiful and deliciously 

 sweet plant, especially after a shower of rain. I once came upon a wood 

 in North Wales carpeted in places with this species, and the perfume was 

 most fragrant. 



On the surface of the bed dwarf British Sedums and Saxifrages will 

 give the necessary carpeting and keep it cool and moist. One precaution 

 here is necessary. In such a bed wire-worms are apt to give unwelcome 

 attention to the fleshy tubers of the Orchis, and, to keep the bed free, 

 carrots should be buried near the plants and occasionally examined for 

 the pests. 



In the third part of the bed, soil of a calcareous nature should be 

 used, this should consist of limestone, or chalk, mixed with sandy loam. 

 In such soil Orchids from chalk or limestone soils may be successfully 

 grown. 



Orchis pyramidalis when once established in such a soil forms a fine 

 ornamental plant easy to cultivate and lasting well in a cut state. Like 

 several other species of the same genus it is variable in colour — this can 

 be well seen on the chalk downs near Henley-on-Thames. 



Another plant worth cultivating in such a position is the Lady's- 

 tresses (Spiranthes autumnalis) ; its interesting little white flowers, 

 twisted like a curl (hence its name), are most welcome in the early 

 autumn after all the summer flowering species have gone. This Orchid, 

 like one or two other of our native Orchids, has the strange habit of 

 disappearing from its usual place of flowering. I know a few plants that 

 grow upon a chalk outcrop on the borders of Herts, where they have 

 grown and flowered for many years, but occasionally one looks for them 

 in vain, and no trace of either loaf or flower can be found ; the next 

 season, however, they are there after their long rest. 



There are two species of Ceplialanthera, C. grandiflora and C. ensi- 

 folia, that repay cultivation in chalky soil ; the former, the white 



