242 



TWENTY-FIRST REPORT. 



Lip hastate or lanceolate. 

 Lip hastate, Avith a tubercle 

 at the base; uppermost 

 leaves narrowly lanceo- 

 late 5. 



Lip lanceolate, entire; lat- 



eia.1 sepals free 8. 



B. Flowers without a conspicuous spur. 



Flowers in slender, more or less twisted spikes, 

 whitish or yellowish- white ; leaves 2-5, usually 



linear or linear-lanceolate 17. 



Flowers not in twisted spikes; inflorescence 



various ; leaves broader, or when linear only 1. 



C. Perianth at least 15 mm. across; flowers 



more or less pink, red or purplish (only 



the sepals purple in Isoti-ia). 



D. A solitary basal linear or linear- 

 lanceolate leaf present, visible 

 during or after anthesis. 

 Flower single, large (2.5-5 cm. 



long), rose-purple 15. 



Flowers several, racemose ; pur- 

 plish pink, 2-3 cm. long. ... 16. 



D. Leaves usually several (1 in Cy- 

 therea) ; not linear. 

 Leaf 1, round-ovate; flower soli- 

 tary; lip saccate 22. 



One or more eauline leaves 

 present. 



Flowers several, pale purple, 

 sometimes white, in the 

 axils of ovate, sessile leaves 14. 



Flowers usually solitary, ter- 

 minal, more or less nodding. 

 Leaves 1-3, ovate-lance- 

 late; flowers pale rose 

 color 12. 



Leaves in a whorl of 5 near 

 the summit of stem; 

 sepals and petals linear . 13. 



Perularia flava. 

 Limnorchis. 



Ihidium. 



Arethusa bulbosa. 



Limodorum tubero- 

 sum. 



Cytherea bulbosa. 



Triphora iriantho- 

 phora. 



Pogonia ophio- 

 glossoides. 



Isotria verticillata. 



