LORANTHACEAE. 101 



Plant greenish-brown ; accessory branches merely leaf-bearing (on Caryopitys 

 edulis and monophylla) . 4. R. divaricata. 



Branches 3-4 mm. in diameter (on Pinus scopulorum, and ponderosa) . 



5. R. cryptopoda. 



I. Razoumofskya americana (Nutt.) Kuntze. {Arceuthobium Americanum 

 Nutt.) Parasitic on Pinus Murrayana, contorta and divaricata, from Sask. 

 and B. C. to Colo, and Ore. — Dillon; Grand Lake; Sunset. 



a. Razoumofskya Douglasii (Engelm.) Kuntze. {A. Douglasii Engelm.) 

 Parasitic on Pseudotsuga, from Ida. to N. M. — ^South Cheyenne Caiion; El 

 Paso Co. ; West Mancos Canon. 



3. Razoumofskya cyanocarpa A. Nels. Parasitic on Pinus Aexilis, from 

 Wyo. to Colo. — Cheyenne Mountain. 



4. Razoumofskya divaricata (Engelm.) Kuntze. {A. divaricatum Engelm.) 

 Parasitic on Caryopitys edulis and monophylla. — Mancos ; Dillon. 



5. Razoumofskya cryptopoda (Engelm.) Coville. {Arceuthobium crypto- 

 podum Engelm. ; A. rohustum Engelm.) Parasitic on Pinus scopulorum and 

 ponderosa. — Between Sunshine and Ward, Boulder Co.; West Indian Creek; 

 Custer Co. ; Stove Prairie Hill ; Rist Canon. 



Family 43. SANTALACEAE R. Br. Sandal -wood Family. 

 I. COMANDRA Nutt. Bastard Toad-flax. 



I. Comandra pallida A. DC. On plains and hills from Man., Alb. and B. C. 

 to N. M. and Utah. — Alt. 4000-8000 ft. — Van Boxle's ranch, above Cimarron; 

 Cucharas River, below La Veta; Wahatoya Creek; Los Pinos; Steamboat 

 Springs ; Mancos ; Fort Collins ; Boulder ; Dolores ; along Poudre River ; 

 Horsetooth Gulch; Colorado City; Pinkham Creek, Larimer Co. 



Order 23. POrYGONALES. 

 Family 44. POLYGONACEAE Lindl. Buckwheat Family. 



Flowers subtended by involucres; stamens 9. i. Eeiogonum. 



Flowers not involucrate ; stamens 4-8. 

 Stigmas tufted. 



Perianth 6-parted ; styles 3-parted ; achenes 3-angled. 2. Rumex. 



Perianth 4-parted ; style 2-parted ; achenes lenticular. 3. Oxyria. 



Stigmas capitate. 

 Leaf-blades jointed at the base; ochreae 2-lobed, becoming lacerate; filaments 

 at least the inner dilated. 4- Polygonum. 



Leaf-blades not jointed at the base ; ochreae not 2-lobed ; filaments slender. 

 Ochreae cylindric, truncate. 5- Peesicaria. 



Ochreae oblique, more or less open on the side facing the leaf. 

 Simple strict herbs with terminal spikes; perianth-lobes not keeled. 



6. BiSTORTA. 



Twining vines with flowers in axillary clusters ; outer perianth-lobes 

 winged or keeled. 7- Tiniaria. 



I. ERIOGONUM L. 



Achenes 3-winged; perianth not accrescent. I. Alata. 



Achenes merely 3-angled ; perianth accrescent in fruit. 

 Perianth with a stipe-like base. 



Involucres in branching cymes. IL Eriantha. 



