Source: Hawksworth and Wiens (1976)
¹ The term "merous" refers to 3-parted and 4-parted. There are 3 or 4 sepals, petals, stamens, etc.
* Only one flowering specimen of this species was available.

This species is presently known only from several sites in Kenya and Ethiopia (Fig 15) (Hawksworth & Wiens 1996) although the host tree is widely distributed from the Arabian Peninsula southward to eastern Zaire and Zimbabwe (FAO 1986). In Kenya, this dwarf mistletoe has been implicated as one of a number of factors involved in an extensive dieback and mortality of J. procera in some, but not in all affected areas (Ciesla et al 1994).

Arceuthobium juniperi-procerae has either two flowering periods or a long flowering period with two peaks. This is in contrast to the other two juniper infesting species, which flower annually in September and October (Hawksworth and Wiens 1976).

3.3.  ARCEUTHOBIUM OXYCEDRI

3.3.1.  SYNONYMY - Arceuthobium oxycedri is the type species of the genus Arceuthobium and, as such, has a long taxonomic history (Hawksworth & Wiens 1976, 1996):

Type locality is France, without a specific location given.

3.3.2.  HOSTS - Arceuthobium oxycedri infects a large number of Juniperus spp. across its natural range and has also been known to infect species of Chamaecyparis, Cupressus and Thuja although it is interesting to note that Cupressus sempervirens, which occurs naturally in portions of Mediterranean Europe and the Near East, has not been reported as a host. Infections on trees representing species of the genera Chamaecyparis, Cupressus and Thuja are all the result of either artificial inoculations or exotic trees having been introduced into areas within the natural range of this dwarf mistletoe. There is also a report of infection on the North American juniper, J. virginiana, in the Ukraine (Isikov & Zakharenko 1988). J. oxycedrus and J. communis are the most commonly reported host plants in Europe and J. oxycedrus is the most commonly reported host plant in North Africa (Tables 6-7). J. oxycedrus is also reported as the principle host of A. oxycedri on the Crimean Peninsula of the Ukraine (Isikov 1986, Isikov & Zak 1988).

The complex taxonomy of Juniperus spp within the natural range of A. oxycedri makes compilation of a comprehensive host list for this dwarf mistletoe difficult, especially for the Near East and Asian portions of its range. Unfortunately, the host list presented by Hawksworth & Wiens (1996) contains errors in botanical nomenclature. The following host list is based on nomenclature of Juniperus spp. given by two authorites, (Rushforth 1987 and Vidakovik 1991):

Chamaecyparis thyoides*
Cupressus arizonica*
Cupressus macrocarpa*
Juniperus communis
Juniperus drupacea
Juniperus excelsa (Synonyms - J. macropoda?, J. polycarpus)
Juniperus foetidissima
Juniperus macrocarpa
Juniperus macropoda (Synonym - J. seravishanica, possible synomym of J. excelsa)
Juniperus oxycedrus (Synonym - J. rufescens)
Juniperus phoenicia
Juniperus sabina
Juniperus semiglobosa (Synonym - J. servascanica)
Juniperus tibetica
Juniperus turkestanica
Juniperus virginiana*
Juniperus wallichiana
Thuja orientalis*

Species with an asterisk have been introduced into the natural range of A. oxycedri and summaries of the geographic distributions of various Juniperus hosts of A. oxycedri are given in the annex. Hosts infected by various countries is summarized in Tables 6-8.

3.3.3.  DISTRIBUTION -.Arceuthobium oxycedri has the widest distribution of all of the known species of dwarf mistletoes and extends over 100^o of latitude or about 10,000 km from Spain and Morocco east through the Mediterranean Region, the Caucuses and the Himalayas to southwestern China (Figs 14-16, Tables 6-8). Distribution within this range is reported to be spotty, however. Elevation range is generally 1,000-2,500 m but it can be found as low as 550 m in Italy and as high as 2,700-3,100 m in Pakistan and up to 3,000-3,500 m in southwestern China (Hawksworth & Wiens 1996).

3.3.4.  DAMAGE - While there are many reports of the occurrence of A. oxycedri, there are relatively few reports of damage or impacts caused by this parasite. Those few reports which do occur indicate that this dwarf mistletoe can cause potentially serious damage to host plants throughout its range.

According to a paper by Lararev and Grigorov (1980), A. oxycedri was relatively rare on the Crimean Peninsula of the Ukraine in 1908 but now causes significant damage, especially along the Peninsula’s southern shore. In a single 0.25 ha study plot, 238 of 262 trees (90.8%) were infected and 135 (51.5%) of the trees had been killed. At elevations of 500-600 m, an infection rate of 10-20% was reported.

Rios Insua (1984) provides some insights into damage caused by A. oxycedri in natural forests of Juniperus near Madrid in central Spain and reports that the level of infection was increasing to the point that research studies were justified. He tested applications of the herbicides 2-4D and 2-4-5T applied to infected portions of trees. While there was reportedly no adverse effects of the herbicides on the host trees, no data on the efficacy of the treatments is given. Rios Insua (1987) also reports that A. oxycedri caused problems to ornamental plants in residential areas, especially Cupressus arizonica and Juniperus communis.

No mention is made of the type of witches brooms caused by A. oxycedri in either Hawksworth & Wiens 1977 or 1996. Examination of infections in Balochistan by the author indicate that they are of the non-systemic or anisophasic type.

Figure 14 - Generalized distribution of A. oxycedri in Europe

Figure 15 - Generalized distribution of A. oxycedri and A. Juniperiprocera in Africa

Figure 16 - Generalized distribution of A. oxycedri in Asia and the Near East

¹ Locations in italics could not be confirmed on maps or atlases either due to size of location, name change or possible misspelling in original report.
² C. = Cupressus, Ch.= Chamaecyparis, J. = Juniperus, T.= Thuja

¹ Locations in italics could not be confirmed on maps or atlases either due to size of location, name change or possible misspelling in original report.
² C. = Cupressus, Ch.= Chamaecyparis, J. = Juniperus, T.= Thuja. Species listed in parenthesis have a questionable status (See Annex 1).
³ The population of J. excelsa in Balochistan has also been referred to as J. ploycarpos and J. macropoda (Beg 1973, Brandis 1907, Jamal and Beg 1974)

An early report by Brandis (1907) indicates that A. oxycedri often kills Juniperus excelsa (reported as J. macropoda) at elevations of 9000-11000 ft (ca 2700-3350 m) in the Upper Chenab River Basin of northern Himachal Pradesh, India. Greater detail is provided in a later report by Bhattacharyya and Uniyal (1982) which indicates that A. oxycedri is a common

parasite of J. excelsa (reported as J. polycarpos). Heavily infected trees die after a few years. While there are indications of much damage to standing trees, infections are reportedly localized and scattered.

Fataliev (1987) reports that in Azerbaijan, A. oxycedri, causes decreased growth of affected trees, deformity and often high levels of mortality, especially in plantations. He recommends that presence of dwarf mistletoe infections should be taken into account when selecting evergreen species for forest plantings.