terrestrial Orchidece of Australia. 427 



years ; and, I have no doubt, many of these Orchideae have con- 

 tinued to flourish in half an inch square of earth for ages. 



In Jig. 84. *2, a shows the coated root cut down the mid- 

 dle, the black part of which is intended to represent part of the 

 bulb filled with the new root, as it appears at the time of flowering; 

 and b shows the part of the bulb filled with the old root. 



The coated orchises grow mostly on the exposed sides of the 

 hills, where the soil is a strong loam mixed with a large portion 

 of gravel, and where their numerous coats must be of great use 

 in protecting their roots from the excessive heat of the summer 

 sun. All the time they appear above ground, the weather with us 

 is seldom warmer than it is in the month of May in England. 

 The leaves of the hinged orchis. No. 5. {jftg. 84. 5.) are of a livid 

 green, somewhat reticulated, and frequently with a red margin. 

 No. 7. {Jig. 84. 7.) diiFers from it, in having the leaves shining yel- 

 lowish green, the insect-like part turned in a different way, and 

 it has some red hair, or hair-like glands, about the neck. No. 8. 

 {Jig. 84. 8.) I have discovered since I wrote the first part of 

 this letter. It has five or six flowers on a spike ; the leaves are 

 oblong heart-shaped, they do not lie so flat on the ground as 

 in the other two species; the hinge on which the insect-like part 

 moves is sessile ; the divisions of the perianth agi'ee with the 

 other species, four of them are turned back by the germen, and 

 one stands up behind the upper lip. The flower-stalk is thicker 

 towards the top, and somewhat succulent, which, perhaps, en- 

 ables the plant to produce its flowers and seed, as I observe the 

 leaves are withered at the time the plant comes into flower. 

 The upper lip is very curious, as you will observe in the dried 

 specimens. This species is found on exposed spots on the sides 

 of the Darlinof range of hills. 



The specimens No. 6. {fig. 84. 6., in which a a are the new 

 roots, and b shows the old roots,) are meant to show the great 

 distance at which some of the Australian Orchideae produce 

 their new bulbs from the old roots : in one species (which I have 

 not room for in this parcel), I have traced them for more than a 

 foot. I can perceive no difference between the roots which end 

 in bulbs, and those which apparently do not; but I think that, 

 if all the roots were to end in bulbs, the plants would be more 

 common than they are; it is a very difficult operation to take 

 up the roots of the Orchideae without separating the bulbs. 



We have a fine showy orchis here (a species of ? Diurus), 

 which propagates freely by the roots, and which, I have no 

 doubt, would answer well in the open air in England, if the 

 roots were treated like the roots of the Persian ranunculus, and 

 kept in a dry warm room in winter. The roots of the flower- 

 ing plants are about 6 in. long, and resemble a good deal the 

 roots of Anthericum Liliastrum; being thickest at the end farthest 



