88 Key to the System of 



Leaf thinly cylindrical, never more than one. 



Younger tuber close to the older ; leaf rarely absent or 

 diminutive ; flowers often small, in a spike ; upper (by 

 reversion lower) calyx-lobe broadish or quite broad; lower 

 (by reversion upper) two often connate; labellum callously 

 thickened, but frequently broad-membranous towards the 

 margin ; pollen powdery ; fruit very short, often very 

 oblique. Frasophyllum. 1759 



436. Flowers spirally arranged in a spike. 



Root-fibres fascicular, tuberously thickened ; stem-leaves 

 when present narrow ; flowers often small, reddish or 

 whitish ; upper calyx -lobe and petals convergent or co- 

 herent ; pollen powdery. Spi'ranthes. 1768 



Flowers variously but never spirally arranged ... 437 



437. Labellum quite similar to the two other petals and to 



the calyx-lobes. 



Younger tuber close to the older ; well developed leaves 

 usually one only, often narrow and elongated ; empty 

 bracts one to three ; flowers in a raceme, sometimes only 

 two or one, of tener blue than yellowish or reddish ; pollen 

 powdery. Thelymitra. 1769 



Labellum quite dissimilar to the two other petals and 

 to the calyx-lobes ... ... ... .. ... 438 



438. United stamens and style abbreviated 439 



United stamens and style elongated ... ... ... 443 



439. Labellum densely beset on the surface with almost 



hairlike somewhat callous prolongations. 



Younger tuber close to the older; leaves always narrow, 

 usually only one well developed, one or two abbreviated 

 or bract-like ; flowers in racemes ; upper calyx-lobe very 

 concave ; petals with broad base sessile ; pollen powdery. 



Calochilus. 1777 



Labellum without any hair-like prolongations ... 440 



