110 ALISMACEiE. 



1. ALISMA, Linnaeus. 

 1. A. Plantago, L. Scape with branches in whorls: leaves ovate to lanceolate or 

 narrower: petals small, white or pinkish. In water or mud. 



2. DAMASONIUM, Jussieu. 



1. D. Californicum, Torr. Scapes 6-18 in. high: leaves ovate to narrowly lanceolate, 

 long-petioled: flowers in 3 or 4 whorls; pedicels 1-2 in. long: petals 3-4 lines long, 

 incised above, white. In water or mud. S. N. Mts. 



3. SAGITTABIA, Linnaeus. 



1. S. variabilis, Engelm. Leaves ovate-sagittate or some linear: flowers mostly ia 

 3's: petals white, rounded |-| in. long: tubers edible. In water or mud. 



ORCHID ACE JG. 



Herbs with a more or less irregular perianth of 3 sepals and 3 petals; the lower petal 

 (made so by a twist in the inferior ovary), called the lip, usually unlike the other two 

 which generally resemble the sepals. Stamens and style united to form the column which 

 is capped by a single perfect 2-ceIled anther, or (in Cypripedium) ^'Jith a perfect anther 

 on each side of the stigma over w&ich curves a triangular sterile stamen. Our genera are 

 usually grouped in four tribes here briefly defined. 



I. Anther resting lid like upon the column, deciduous: pollen-masses 4 1, S, 3 



II. Anther united with column, persistent on its face above stigma: pollen-masses 2. . 4 



III. Anther erect on top of column, persistent: pollen-masses 2-4 5 to 9 



IV. Anthers 2, lateral; the sterile stamen petaloid, incurved 10 



• Herbs with one to many green leaves: not parasitic. 



Leaf solitary from a globose conn. Scape 1-flowered 1 



Scape 6-20-flowered 3 



Leaves several to many from a creeping rootstock 6 



Leaves a pair below the raceme of small flowers, ovate or cordate 7 



Leaves 2 or 3 to many clasping slender or stoutish stems, at least at base. 

 Flowers not leafy-bracted, white or greenish, in spikes or racemes. 



Lip of perianth spurred at base , , .»-.■. • . .♦ 4 



Lip not spurred: spike twisted: flowers 3-ranked 6 



Flowers leafy-bracted, pedicellate, 1-2D. 



Lip concave at base, constricted in middle 8 



Lip an inflated sac, the mouth with incurved margin 10 



* * Plants toith vx> green leaves: stems simple, scape-Uke. 



