372 LORANTHACEAE 



4. P. californicum Nutt. Stems slender, terete, hanging or pendulous from 

 the host; herbage pubescent or finally glabrous; scales broadly ovate, acute, 

 spreading; staminate spikes consisting of 2 or 3 (or 5) flower-bearing joints, 

 each with 2 to 6 flowers; anthers oblong, the cells opening by a longitudinal 

 slit; pistillate spikes sometimes with nearly as many joints and flowers as the 

 staminate; joints in fruit elongated (2 to 12 lines long) ; berries red, 2 lines 

 in diameter. 



Southern California along the Colorado River and in the Colorado Desert. 

 Arizona. Parasitic on Prosopis juliflora and pubescens, Larrea mexicana, 



Acacia greggii, etc. 



Locs. Imperial, Eoadhouse; Indio, Davy 45; Mecca, Mary McKibben; Cottonwood Sprs., 

 Hall 6014; Mellen, Colorado River, Jepson 5195. 



Eef. PHORADENDRON CALIFORNICUM Nutt. Jour. Acad. Phila. ser. 2, 1: 185 (1848), type 

 loc. Southern California, Gambel, parasitic on Prosopis pubescens. 



5. P. juniperinum Engelm. Stems stout, terete, in erect tufts, 6 to 12 

 inches high, the ultimate branchlets 4-sided; scales low-triangular, ciliate, 

 distinct or connate; staminate spikes consisting of 1 (rarely 2) very short 

 joints; joints 6 to 8-flowered; anthers tranverse, opening by pores; pistillate 

 spikes 2-flowered; berry whitish or light red, 11/2 lines in diameter. 



Sierra Nevada, on Juniperus. East to New Mexico. 



Var. libocedri Engelm. Branches longer and more slender; joints more 

 elongated. Sierra Nevada south to the San Bernardino and San Jacinto 

 mountains, on Libocedrus decurrens. 



Befs. PHORADENDRON JUNIPERINUM Engelm. Mem. Am. Acad. ser. 2, 4: 58 (1849), type 

 loc. Santa Fe. Var. LIBOCEDRI Engelm. Bot. Cal. 2: 105 (1880), type Calif ornian. 



2. ARCEUTHOBIUM Marsch-Bieb. PINE MISTLETOE. 



Plants yellow or brown, leafless, fragile- jointed, parasitic on coniferous 

 trees. Stems quadrangular or angled. Leaves reduced to connate scales. 

 Flowers solitary or several in each axil, crowded into apparent spikes, open- 

 ing in autumn. Staminate flower : calyx mostly 3-parted, compressed ; stamens 

 3, the anthers sessile near the center of the calyx-lobes, roundish, 1-celled, 

 opening by a circular slit. Pistillate flower: calyx 2-cleft, the teeth laterally 

 disposed, the ovary ripening the next autumn after flowering and exserted 

 on the recurved pedicel. Berry circumscissile near the base, when fully ripe 

 explosively dehiscent at a touch or when teased, the glutinous seed being ex- 

 pelled to a distance of several feet. Northern hemisphere, 10 species. (Greek 

 arkeuthos, juniper, and bios, life.) 



Staminate flowers on peduncle-like joints in a paniculate cluster 1. A. americanum. 



Staminate flowers in the axils of the scales of a simple or compound spike. 



Host-plant Pseudotsuga 2. A. douglasii. 



Host-plant Pinus species. 



Staminate plants yellow, pistillate ones brown 3. A. campylopodum. 



Staminate and pistillate plants of the same color or nearly. 



Branches erect; staminate flowers many 4. A. cryptopodum. 



Branches divaricate; staminate flowers often few 5. A. divaricatum. 



1. A. americanum Nutt. Plants greenish yellow, dichotomously or verti- 

 cillately much branched; staminate flowers nearly all terminal on distinct 

 peduncle-like joints. 



Sierra Nevada from the Yosemite region northward to British Columbia 

 and east to the Rocky Mts. On Pinus murrayana. 



Locs. N. Pork Kings Eiver, Hall $ Chandler 426 ; Little Yosemite Valley, Bolander 5095. 



Eefs. ARCEUTHOBIUM AMERICANUM Nutt.; Engelm. in Gray, Jour. Bost. Soc. Nat. Hist. 

 6: 214 (1850), type from Oregon, Nuttall. EazoumofsTcya americana Kuntze, Rev. Gen. PI. 

 2: 587 (1891). 



2. A. douglasii Engelm. Small, the stems suberect, ^4 to 1 inch high; 

 flowers in short usually 5-flowered spikes; berry 2y 2 lines long. 



