MISTLETOE FAMILY 371 



Berry sessile; flowers globose; leaves foliaeeous or scale-like 1. Phoeadendron. 



Berry ou a recurved pedicel; flowers mostly compressed; leaves scale-like and connate 



2. Arceuthobium. 

 1. PHOEADENDRON Nutt. Mistletoe. 

 Parasitic on mostly deciduous trees, the stems nuieh branched and swollen 

 at the nodes. Leaves foliaeeous and coriaceous, or scale-like. Flowers sunk 

 in the joints of the jointed spikes, usually several to each scale. Staminate 

 calyx commonly 3-lobed, the anthers 2-celled, sessile on the base of the lobes. 

 Pistillate calyx adherent to the ovary, the 3 teeth persistent on the globose 

 semitranspareut mucilaginous sessile berry. — North and South America, mostly 

 tropical, 80 species. (Greek phor, a thief, and dendron, a tree.) 

 Leaves foliaeeous; spikes many-flowered; anthers transverse, opening by pores. 

 Leaves elliptic to oblong, 3 or 5-nerved. 



Herbage yellowish 1. P. flavescens. 



Herbage greenish 2. P. rillosum. 



Leaves narrowly oblong or spatulate, nerveless 3. P. bolleanum. 



Leaves reduced to short scales; spikes few-flowered. 



Anthers oblong, opening by longitudinal slits 4. P. californieum. 



Anthers transverse, opening by pores 5. P. junipcrinmn. 



1. P. flavescens Nutt. var. macrophyllum Engelm. Yellow Mistletoe. 

 Foliage yellowish green ; leaves orbicular to ovate or narrowly elliptic, obtuse, 

 3iL> inches long or less, conspicuously 5-nerved from the base and distinctly 

 petioled; fruiting spikes dense, 11/2 inches long or less; berries white, 2 lines 

 in diameter. 



Sacramento and San Joaquin valleys to Southern California and east to 

 Texas. Parasitic on various soft-wood trees: on Aesculus californica (the 

 haustoria spread in the bark and by buds give rise to a twiggy growth) ; on 

 Populus fremonti (the trees are frequently killed by the parasite) ; also 

 occurs on various willows. Stems 1 to 5 feet long, forming a large woody 

 shrub. 



Eefs. — Phoradexdron flavescens Nutt. Jour. Acad. Phila. ser. 2, 1: 185 (1848) by im- 

 plication, the type spm. from Texas. Var. macrophtllum Engelm. Hot. Wheeler, 252 (1878), 

 type spms. from the Gila and Bonita rivers. 



2. P. villosum Nutt. Common Mistletoe. Foliage deep green; leaves 

 elliptic, obtuse, 3-nerved, i/o to 1 inch long, on short petioles; berries pinkish, 

 11/2 lines in diameter. 



Coast Range and Sierra Nevada foothills ; Southern California. Arizona to 

 Oregon. Parasitic chiefly on oaks, observed on the following species : Quercus 

 douglasii, lobata, wislizenii, kelloggii, and chrysolepis, and Umbellularia cali- 

 fornica. Stems woody, forming shrubs 1 to 6 feet in diameter. 



Eefs. — Phor.\dendron villosum Nutt. Jour. Acad. Phila. ser. 2, 1: 185 (1848) by implica- 

 tion; Engelm. in Gray, Jour. Bost. Soe. Nat. Hist. 6: 212 (1850), type loc. Willamette woods. 

 Ore. 



3. P. bolleanum Eichler. Stems i/o to % foot long, thickly branched; leaves 

 narrowly oblong or spatulate, obtuse, contracted to a short petiole, i/o to 1 inch 

 long; bracts ciliolate ; spikes short, mostly less than 14 n^c^ long, opposite 

 or in 4s ; berries pearl-like on account of their whiteness, translueency and 

 luster, rather less than 2 lines in diameter. 



Coast Ranges and Sierra Nevada, through the Mohave Desert to Southern 

 California. South into Mexico. 



Locs. — Hornbrook, Siskiyou Co., Copeland 3542, on Juniperus; Middletown, Jepson, on 

 Cupressus macnabiana; Mt. Tamalpais, Eastwood, on Cupressus sargentii; Santa Monica, 

 Barber 205; Leonis Valley, Davy 2603, on Juniperus. Common in the tops of Abies concolor 

 between Yosemite and Mariposa Big Trees, often finally killing the terminal part (four to six 

 feet) of the axis. 



Refs. — Phoradendron bolleanum Eichler. in Mart. FI. Bras. 5': 134m (1868); Jepson, 

 Fl. W. Mid. C'al. 366 (1901). riscum bolleanum Seem. Bot. Herald, 295, t. 63 (1856), typo loc. 

 Sierra Madre, Mexico. 



