Yew Family

Matthew H. Hils

Trees or shrubs evergreen, usually neither resinous nor aromatic (sharp- or foul-odored in Torreya ), dioecious or monoecious. Bark scaly or fissured. Lateral branches well developed, similar to leading shoots; twigs terete, not densely clothed by leaves but ± ridged by decurrent leaf bases; longest internodes less than 1 cm; buds ± inconspicuous. Roots fibrous to woody. Leaves (needles) simple, persisting several years, shed singly, alternate [opposite], spirally arranged but often twisted so as to appear 2-ranked, linear to linear-lanceolate, decurrent; resin canals present or absent. Pollen cones maturing and shed annually, solitary or clustered, axillary on year-old branches, globose to ovoid, sporophylls bearing 2--16 microsporangia (pollen sacs); pollen ± spheric, not winged. Seed cones reduced to 1--2 ovules subtended by inconspicuous, decussate bracts, maturing in 1--2 seasons, axillary on year-old branches. Seeds 1 per "cone," erect, not winged, hard seed coat partially or wholly surrounded by a juicy, fleshy or leathery aril; cotyledons 2.

Genera 5, species 17--20 (2 genera, 5 species in the flora): mainly Northern Hemisphere.

SELECTED REFERENCES

Burns, R. M. and B. H. Honkala. 1990. Silvics of North America. 1. Conifers. Washington. [Agric. Handb. 654.] Canadian Forestry Service. 1983. Reproduction of conifers. Forest. Techn. Pub. Canad. Forest. Serv. 31. Farjon, A. 1990. A Bibliography of Conifers. Königstein. [Regnum Veg. 122.] Florin, R. 1948. On the morphology and relationship of the Taxaceae. Bot. Gaz. 110: 31--39. Hosie, R. C. 1969. Native Trees of Canada, ed. 7. Ottawa. Pp. 110--111. Krüssmann, G. 1972. Handbuch der Nadelgehölze. Berlin. Little, E. L. Jr. 1979. Checklist of United States Trees (Native and Naturalized). Washington. Pp. 283, 287--288. [Agric. Handb. 541.] Pilger, R. K. F. 1903. Taxaceae. In: H. G. A. Engler, ed. 1900--1953. Das Pflanzenreich... Berlin. Vol. 18[IV,5], pp. 1--124. Pilger, R. K. F. 1916. Die Taxales. Mitt. Deutsch. Dendrol. Ges. 25: 1--28. Pilger, R. K. F. 1926. Coniferae: Taxaceae. In: H. G. A. Engler et al., eds. 1924+. Die natürlichen Pflanzenfamilien..., ed. 2. Leipzig and Berlin. Vol. 13, pp. 199--211. Price, R. A. 1990. The genera of Taxaceae in the southeastern United States. J. Arnold Arbor. 71: 69--91. Silba, J. 1986. Encyclopaedia Coniferae. Phytologia Mem. 8: 1--127.

Lower Taxa

• Taxus Linnaeus
• Torreya Arnott