206 LORANTHACE^. Arceuthobium. 



2. ARCEUTHOBIUM, Bieb. 



Flowers axillary ami teriniiuil, sulitary or several from the same uxil. Starainato 



flowers 2-5- (mostly 3-) parted, compressed or the terminal ones globose before 



opening. Anthers udnate to the lobes, circular and 1-celled, dehiscing by a circular 



slit at base ; pollen-grains spinulose. Pistillate flowers ovate, compressed, 2-toothed, 



subsessile and partly enclosed ; the pedicel at length elongated, exsert and recurved. 



Berry fleshy, compressed, dehiscent at the circumscissile base. Cotyledons very 



short, only indicated by a notch. — Parasitic on conifers, glabrous, with rectangular 



branches and connate scale-like leaves : flowers often crowded into apparent spikes 



or panicles, opening (in our species) in summer or autumn and maturing their fruit 



in the second autumn, when the berries suddenly and forcibly eject the glutinous 



seeds to the distance of several yards. 



A small genus, re]nvscnteil in S. Europe l)j' a single species, and in America ranging from tho 

 northern border of the United States to Mexico, chielly in the mountains. 



* Staminate flowers all (or nearly all) terminal on distinct 2^eduncle-like joints, 



jKaiiculate. 



1. A. Americanum, Nutt. Slender, dichotomously or verticillately much- 

 branched, greenish yellow ; staminate jjlants sometimes 3 or 4 inches long (l to a 

 line thick at base), fertile plants much smaller : flowers small, tho staminate a lino 

 broad or more, with ovate-orljicular acutish lobes, the pistillate a half to one line 

 long: fruit 2 lines long. — Engelm. PI. Lindh. 214, and Wheeler's Pep. vi. 252. 



Only on Finns contorta (and apparently P. Banlnuata in the Saskatchewan region), from 

 Wyoming to Oregon and southward to Colorado and California (Little Yosemite Valley, 

 Bolandcr). Flowering mostly late in autumn apparently, but found by Parrij in Wyondng in 

 flower in July ; fruit mature in August and September. Its .shoots creep along within the tissue 

 of the bark on young branches of the pine, and in the autumn bud out in the form of little knobs 

 among the bud-scales at the end of three-years-old limbs, developing into flowering iilants the 

 ne.xt season. When once established it maj' continue to sjuout from the same base for many (30 

 or more) years, causing hy])ertrophy of the wood and baik of tlie limb and often its linal destruc- 

 tion. Fruiting and llowering branchlets are often seen in juxtaposition in the same whorl, but 

 without leaf-buaring branchlets, and never in superposition. 



The type of the genus, A. Oxyccdri, Bicb., of the Old World, is allied to thi.s, but distinguished 

 from it and from all American s|>ecies by its staminate flowers being all terminal on short branch- 

 lets and usually in threes, scarcely a line wide and with orbicular lobes, and by the much smaller 

 oblong fruit, less than 1.^ lines long. The nortlieastern A. piisillum, Peck, of the Adirondacs, 

 growing on Picca nigra, also belongs to this section. 



* * Staminate flowers axillary {vnth a terminal one), forniinrj sinijtlc or com- 



2)0Hnd spikes. 



-I- Slender, greenish-yellow: accessory branchlets of fruiting sjjccimejis flower- 

 bearing. 



2. A. Douglasii, Engelm. Similar to the last, but smaller, ^ to 1 inch high : 

 branches suberect, solitary, or with accessory ones behind (never beside) the primary 

 ones : flowers in short (usually 5-llowered) spikes ; tho staminate less than a line 

 wide with orbicular-ovate acutish lobes : fruit 2^ lines long. — Wheeler's Pep. 

 vi. 253. 



Var. abietinum, Engelm. A larger form, 1 to 3 inches high (tho fertile smaller) 

 with spreailing or even recurved few-flowereil branchlets : staminate flowers 1^ lines 

 wide : fruit scarcely 2 lines long. 



On Pscudotsuga Thugiasii, from New Mexico to S. Utah and N". Arizona ; tho variety on Jbics 

 concolor in Sierra Valley (J. G. Lcnimon) and S. Utah, Parrij. Flowering apparently in Oct<d)er. 

 Distinguished from the last by its usually smaller size, the superimposed (never verticillate) ac- 

 cessory branchlets, lateral flowers, and larger fruit. Its creeping stroma buds out all along tho 



