ORCIIIDACE^E. (ORCHIS FAMILY.) 497 



Order 114. ORCHIDACE.E. (Orchis Family.) 



Herbs, clearly distinguished by their perfect irregular flowers, with G-merous 

 perianth adnate to the 1-celled ovary, with innumerable ovules on 3 parietal 

 placentce, and with either one or two gynandrous stamens, the pollen cohering 

 in masses. Fruit a 1-celled 3-valved pod, with innumerable minute seeds, 

 appearing like fine saw-dust. Perianth of 6 divisions in 2 sets ; the 3 outer 

 (sepals) mostly of the same petal-like texture and appearance as the 3 

 inner (petals). One of the inner set differs more or less in figure, direc- 

 tion, &c from the rest, and is called the labellum or Up ; only the other 

 two taking the name of petals in the following descriptions. The lip is 

 really the upper or posterior petal, i. e. the one next to the axis, but by a 

 twist of the ovary of half a turn it more commonly is directed forward, as 

 if anterior, i. e. is next the bract. Before the lip, in the axis of the flower, 

 is the column, composed of a single stamen, or in Cypripedium of two sta- 

 mens and a sterile rudiment of a third, variously coherent with or borne 

 on the style or thick fleshy stigma ; the anther 2-celled ; each cell con- 

 taining one or more masses of pollen (pollinia or pollen-masses). Stigma a 

 broad glutinous surface, except in Cypripedium. — Perennials, often tuber- 

 bearing or tuberous-rooted ; some epiphytes. Leaves parallel-nerved, all 

 alternate. Flowers often showy, commonly singular in shape, solitary, 

 racemed, or spiked, each subtended by a bract, — in all arranged for 

 fertilization by the aid of insects, very few capable of unaided self-fertili- 

 zation. (See articles on Fertilization of Orchids, in Sill. Jour. 1862, 

 1863, &e.) — A vast family, but few in the United States. 



I. Anther only one. (The 2 cells should not be mistaken for anthers !) 



Tribe I. OPHRVDEX, Anther (of 2 separate cells) borne on and entirely adnate to 

 the face of the stigma, erect or reclined. Pollen cohering into a great number of coarse 

 grains, which are all fastened by elastic and cobwebby tissue into one large mass, and to 

 a stalk that connects it with a gland or disk which was originally a part of the stigma. 

 Flower in our species ringent, the lip with a spur beneath : one distinct gland to each 

 pollen-mass. 



1. Orcbis. The two glands or viscid disks enclosed in a common pouch. 



2. Habenarta. The two glands or disks naked (without any pouch or covering), either 



approximate or widely separated. 

 Tribe II. NEOTTIEJE. Anther dorsal and erect or inclined, attached by its base- 

 only or by a short filament to the back or summit of the column, persistent. Pollen in 

 our genera loosely cohering (mostly by some delicate elastic threads) in 2 or 4 soft masses, 

 and soon attached directly to a viscous gland on the beak of the stigma. 



3. Gooil yera. Lip entire, free from the column, without callosities at the base. 



4. Spiranthes. Lip ascending and embracing the column below, 2 callosities at the base. 



5. Listera. Lip flat, spreading or pendulous, 2-lobed at the apex. 



Tribe III. ARETHUSE.3E, MALAXIDE^E, &c. Anther terminal and in- 

 verted (except in No 12) like a lid over the stigma, deciduous. 



# Pollen powdery or pulpy, in 2 or 4 delicate masses : no gland. 



6. Arethusa. Lip bearded, its base adherent to the linear column. Pollen-masses 4. 



7. Pogonia. Lip more or less crested, free from the club-shaped column. Pollen-masses 2. 



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