Victorian Plants. 89 



440. Flowers very small. 



Younger tuber distant from the older ; leaves never more 

 than one, always thinly cylindrical; flowers constantly in 

 a spike, often greenish ; upper calyx-lobe very concave ; 

 pollen powdery. Microtis. 1778 



Flowers rather or quite large... ... ... ... 441 



441. Lateral petals comparatively large. 



Younger tuber close to the older; leaves few or several, 

 always narrow, usually channelled ; flowers in a raceme 

 or sometimes only two ; upper calyx-lobe clasping towards 

 the base, straight or spreading towards the summit ; 

 lower calyx-lobes descending, very narrow ; lateral petals 

 dilated, often yellowish ; pollen powdery. Diuris. 1779 



Lateral petals minute or very narrow ... 442 



442. Leaves few, narrow, the upper almost bract-like. 



Younger tuber close to the older; leaves usually channelled; 

 flowers in a spike, greenish, yellowish or the labellum 

 partly dark-purplish ; upper calyx-lobe throughout very 

 concave, towards the summit bent inward ; lower calyx- 

 lobes ascending, very narrow ; lateral petals minute ; 

 pollen powdery. Orthoceras. 1785 



Leaf one, nearly always cordate-orbicular. 



Younger tube distant from the older ; leaf basal, almost or 

 quite sessile or rarely long-stalked and lanceolar, always 

 membranous ; flower singly terminal, on a very short 

 stalk or sessile ; upper calyx-lobe large, very concave ; 

 lower calyx-lobes and lateral petals very narrow and often 

 quite short ; labellum comparatively broad, downward 

 tubular; pollen powdery. Corysanthes. 1786 



443. Leaf one only 444 



Leaves more than one ... ... ... ... 449 



444. Leaf about as broad as long, very seldom elongated ... 445 



Leaf always considerably longer than broad, very 

 seldom quite abbreviated ... ... ... ... 447 



