92 PLATANTHERA FIMBRIATA. GREAT FRINGED ORCHIS. 



the ovary. If we examine the stem, we find the leaves scattered 

 thereon. In the stem growth there has been a gradual elonga- 

 tion, but we see that it takes but three leaves to make a full 

 circle round the stem. We do not notice indications of the 

 spiral growth which takes these leaves round the stem, but it is 

 there. It is the more sudden twisting and arresting of the elon- 

 gating growth that make the set of three sepals and of three 

 petals. These lengthenings and twistings do not go on with 

 regular intensity, but as in waves, sometimes fast and sometimes 

 slow. Such varying intensity and sudden change of degree can- 

 not be seen in many flowers; but this Orchid, as well as some 

 other species, gives a good opportunity for observing it. If we 

 watch the ofrowth of the flower we shall find that it first makes a 

 slow, elongating growth, and that the twisting comes on suddenly, 

 usually taking but a few hours to make a half-turn. In Fig, 2 we 

 have shown an almost mature seed-vessel with the twist towards 

 the base. The torsion in the ovarium is also shown in Fig. 6. 



The Great Frinsfed Orchis seems to have been first made 

 known to botanists through Dr. Pitcairn, who introduced it from 

 Newfoundland to the Kew Gardens in 1777, and it was named 

 Orchis spectabilis by Willdenow twenty years later. Its best 

 home is still found to be in the northeastern portion of the United 

 States. It extends westward from New England to Michigan, 

 being quite a common Orchid in the latter State. In Northern 

 and Central Ohio it is also common, but is found more sparingly 

 in the southern part of the State. In Pennsylvania and New 

 York it is found chiefly in the higher districts, becoming scarcer 

 as it reaches lower elevations. In New Jersey, which in many 

 respects is the home of Orchidacece, it is found only in the more 

 hilly localities in the western part of the State. Our specimen 

 is from Massachusetts. 



Explanation of Plate. — i. Whole plant with root and hollow stem. — 2. Seed-vessel 

 approaching maturity. — 3. Transverse section of the same. — 4. Divergent gland of the 

 anther-cells. — 5. Full-face view of single flower. — 6. Side view of flower. 



