66 



3a. Stem-leaves minute, linear-subulate; stem slender, erect, 37 



dm. high (flowers pink; summer) 



Milkwort, Polygala incarnata. 

 3b. Stem-leaves narrowly oblong or broader; stem generally 1 4 



dm. high ! 4. 



4a. Flowers in a short thick obtuse very dense spike (flowers 

 greenish or purple; summer) Milkwort, Polygala sanguinea. 



4b. Flowers in a slender tapering spike 5. 



4c. Flowers in a raceme; plants with subterranean flowers also 

 (flowers purple; early summer) Milkwort, Polygala polygama. 



5a. Leaves linear or nearly so (flowers purple; summer) 7b. 

 5b. Leaves lanceolate or oblong-lanceolate, 2 6 cm. long (flowers 

 white; late spring) Seneca Snakeroot, Polygala senega. 



5c. Leaves ovate to ovate-lanceolate (flowers white; late spring) 



Seneca Snakeroot, Polygala senega var. latifolia. 

 6a. Spike oval, thick, obtuse Milkwort, Polygala cniciata. 



6b. Spike acute 7. 



7a. Spike densely flowered, 1 2 cm. long 



Milkwort, Polygala verticillata. 

 7b. Spike loosely flowered, 2 5 cm. long 



Milkwort, Polygala yerticillata var. ambigua. 



EUPHORBIACEAE, the Spurge Family 



Herbs, with alternate, opposite, or whorled leaves and usually 

 milky juice. Flowers small or minute and inconspicuous, without 

 petals and frequently without calyx. In our commoner species, sev- 

 eral staminate flowers, each consisting of a single stamen only, and 

 one pistillate flower, consisting of a single pedicelled 3-lobed ovary 

 only, are included within a 4 5-lobed involucre, which is sometimes 

 colored and resembles a calyx or corolla. 



la. Stem-leaves alternate; inflorescence axillary; flowers with calyx 

 and several stamens (3 8 dm. tall; flowers greenish or pur- 

 plish; summer) (Three-seeded Mercury) 2. 



Ib. Stem-leaves opposite, usually inequilateral at base; flowers as 

 described for the family; apparent flowers in axillary clusters 

 (summer and autumn) (Spurge) 3. 



Ic. Stem-leaves alternate; inflorescence a terminal umbel-like cluster, 

 with its branches subtended by opposite or whorled leaves; 

 flowers as described for the family (Spurge) 9. 



2a. Leaves ovate or ovate-lanceolate; flower-clusters shorter 

 than the subtending bract 



Three-seeded Mercury? Acalypha virginica. 



2b. Leaves lanceolate to oblong; flower-clusters equaling or ex- 

 ceeding the subtending bract 



Three-seeded Mercury, Acalypha gracilens. 



