GENUS CRATAEGUS (HAWTHORN) FROM ALASKA TO CALIFORNIA

This paper covers the known Crataegus L. (Rosaceae) species of Alaska, British Columbia, Oregon, Washington, California, Idaho and Montana. Recent discoveries based on extensive fieldwork by the author and R.J. O'Kennon in the western states and British Columbia, insights coming from the biosystematic studies of Dickinson and associates and work by Brunsfeld and Johnson on C. douglasii and relatives have radically altered the views of Crataegus of this area previously held to comprise only three native species: one black-fruited - C. douglasii Lindl. with its two varieties, var. douglasii and var. suksdorfii (Sarg.) Kruschke; and two red-fruited - the C. piperi Britton of this region, but generally called C. columbiana, and C. macracantha Lodd. ex Loud. reported for Montana, but frequently called C. succulenta Schrad. ex Link or C. occidentalis Britton in the west. In addition the red-fruited introduction C. monogyna Jacq. was widely reported. My work (Phipps, 1998; Phipps and O'Kennon, 1998) greatly extends the range of C. macracantha and adds three more species for the region. I believe that further novelties are still to be expected here. I give below a key to the Crataegus taxa, shortness of notice for preparation of which (only one week) has precluded detailed testing, together with brief notes on some of the species. It is interesting to note that the majority of species are in the purple to black-fruited group.

KEY

Note: 'Leaves' refers to short-shoot leaves only.

1. Leaves with veins to the sinuses; thorns, at least some of them, indeterminate and growing out into twigs; introduced species:

2. Leaves deeply 5-7 lobed, leaf incision index > 50%, lobes acute; style and nutlet 1
.......................................... 1. C. MONOGYNA

2. Leaves shallowly 3-lobed, leaf incision index usually < 30%, lobes obtuse, terminal usually largest; styles and nutlets 2
......................................... 2. C. LAEVIGATA

1. Leaves lacking veins to sinuses; thorns all determinate; native species:

3. Fruit bright red at full maturity, generally more or less orange a month before:

4. Autumnal color of leaves generally yellow in this area; one-year old twigs fawn, golden-green or pale tan; early flowering; nutlets not pitted laterally
................................... 10. C. CHRYSOCARPA

4. Autumnal color of leaves bronze in this area; one-year old twigs usually dark purple-brown; late flowering; nutlets pitted laterally
................................... 11. C. MACRACANTHA

3. Fruit purple to black at full maturity, in some bright red about a month prior to this:

5. Leaves ovate, lobes subacute to obtuse; inflorescence branches densely hairy; fruit orbicular, hairy;
....................................... 9. C. PHIPPSII

5. Without above combination of characteristics:

6. Thorns fine, usually straight; older twigs and young branches usually shining copper-colored; leaf blades generally at least 2 x as long as wide; stamens 10
................................... 3. C. RIVULARIS

6. Thorns stouter, often slightly recurved; 2-year old twigs usually very deep brown, often purple-brown; leaf blades usually about 1.5 x as long as broad; stamens 10 or 20:

7. Thorns 2-6 cm long; calyx lobes glandular-serrate, acute, erect to spreading in fruit; fruit bright red a month before full maturity, flask shaped:

8. Leaves thin, sharply lobed; anthers pink; very late anthesis; calyx lobes in fruit reflexed
............................ 7. C. WILLIAMSII

8. Leaves coriaceous, less sharply lobed; anthers white; early to mid-season anthesis; calyx lobes in fruit spreading
......................... 8. C. OKANAGANENSIS

7. Thorns usually about 2.5 cm long; calyx lobes scarcely glandular and not serrate, blunt, shorter, in fruit appressed; fruit often black but occasionally vinous or chestnut-coloured (but not bright red) a month before full maturity:

9. Stamens 20; leaf blades obscurely or not lobed, lobes usually blunt
............................ 4. C. SUKSDORFII

9. Stamens 10; leaf blades usually clearly, though not necessarily very deeply, lobed, lobes usually subacute to acute:

10. Flowers 12-15 mm in diameter; fruit ellipsoid, usually black or dark vinous a month before full maturity
......................... 5. C. DOUGLASII

10. Flowers 15-18 mm in diameter; fruit ampulliform, usually vinous or chestnut at a month before full maturity
......................... 6. C. OKENNONII

NOTES ON TAXA KEYED

1. C. MONOGYNA Jacq.

Common at low altitudes in northwestern WA, southwestern coastal BC; scattered elsewhere; AK, interior BC, interior WA, CA, OR, MT. Hybridizes locally with C. douglasii (Love and Feigen, 1978)

2. C. LAEVIGATA (Poir.) DC.

For first accurate wild record of this species for North America see Phipps (1998). Very rare, WA. The double red-flowered cultivated hawthorns usually attributed here are C. x media Bechst.

3. C. RIVULARIS Nutt. ap. Torr. & A. Gray

Southern ID (fairly common) and southwards. Apparently no intermediates with C. douglasii, with which range is allopatric. Quite different from latter species (see Phipps, Sida, submitted).

4. C. SUKSDORFII (Sarg.) Kruschke

Resuscitated as a species by Brunsfeld and Johnston (1990) with good arguments. Rather variable, however. AK, BC, WA, OR, CA, ID, MT.

5. C. DOUGLASII Lindl.

Common and widespread in area OR, WA, BC, ID, MT. Rather variable and segregates or varieties might be recognized.

6. C. OKENNONII J.B. Phipps

Segregate from C. douglasii with larger flowers, different leaves, fruit and growth habit. For more detail see Phipps & O'Kennon (1998). WA, BC, ID, MT.

7. C. WILLIAMSII Eggl.

A perfectly good species of northwest MT ignored by all floras since its description. Very late flowering and easy to recognize. See Phipps (1998).

8. C. OKANAGANENSIS J.B. Phipps & O'Kennon

Surprisingly, for a new species, very common from Okanagan of BC and WA to northwest MT. Could only be confused with C. williamsii of species listed here. See Phipps and O'Kennon (1998). St. John (1963) may have alluded to this species in his Flora of southeastern Washington and adjacent Idaho. Fred Johnson was the only person to collect this species in substantial numbers before ourselves.

9. C. PHIPPSII O'Kennon

The most distinct of the species recently described and scattered from BC and WA to MT. See Phipps and O'Kennon (1998).

10. C. CHRYSOCARPA Ashe

Includes C. piperi Britton and "C. columbiana Howell" of floras. See Phipps (1998) for discussion of correct name. I recognize two varieties. BC, WA, OR, ID, MT.

11. C. MACRACANTHA Lodd. ex Loud.

O'Kennon and I extend its range westward to ID, WA, OR and BC. It is quite common in the Okanagan and easily distinguished, at all seasons, from any other Crataegus treated here.

I would like to take this opportunity to take my hat off to an old friend, Bill Weber, greatly deserving of this Festschrift. It is perhaps symbolic that Colorado, of all the western states (west of the Rockies) has been the only one with several Crataegus species not to have its list altered in the slightest by recent work.

References:

Brunfeld, S.J. and F.D. Johnson. 1990.

Cytological, morphological and phenological support for specific status of Crataegus suksdorfii (Rosaceae). Madrono 37: 274-282.

Love, R. & M. Feigen. 1978.

Interspecific hybridization between native and naturalized Crataegus (Rosaceae) in western Oregon. Madrono 25: 211-217.

Phipps, J.B. 1998.

Introduction to the red-fruited hawthorns of western North America. Canad. J. Bot. 76 (July issue, in press )

Phipps, J.B. & R.J. O'Kennon. 1998.

Three new species of Crataegus (Rosaceae) from western North America. C. okennonii, C. okanaganensis and C. phippsii. Sida 19: 169-191.

St. John, H. 1963.

Flora of southeastern Washington and adjacent Idaho, 3rd ed. Outdoor Pictures, Escondido, California.

DISTRIBUTION OF THE CLADONIACEAE IN WESTERN NORTH AMERICA

In our recent study (Goward & Ahti, 1997), we have examined the western North American distributions of 84 taxa and chemotypes of Cladinae and Cladoniae occurring at temperate and boreal latitudes. Our analysis was drawn primarily from the maps and text of Goward, Ahti & Brodo (in prep.: based on approximately 8,200 specimens!), and secondarily from those of Geiser et al. (1994), Hammer (1995), and Thomson (1984). We propose six broad conclusions, some of which may be of general interest to students of phytogeography:

1. Western North America's richest assemblage of Cladina and Cladonia, with between 76 and 78 taxa, occurs in British Columbia between 52°N and 56°N, in a region covered by glacial ice until roughly 13,000 to 10,000 years ago.
2. South of 52°N, species diversity declines dramatically, with a loss of between three and five taxa per degree of latitude.
3. With the exception of those species able to persist in nunataks at alpine elevations, or under arctic conditions to the north of the ice, or again in small, periglacial refugia along the west coast, most of British Columbia's Cladoniaceae must have passed the Pleistocene south of the Cordilleran Icesheet.
4. Floristic and chemical diversity in the Cladoniaceae are greater in humid regions than in arid regions, and at lower, forested elevations than at upper, alpine elevations. Many species can therefore be assumed to require habitats subject to only relatively brief periods of desiccation.
5. Given that many Cladoniaceae probably passed the Pleistocene south of the Cordilleran Icesheet, the absence of numerous species from all or most of Washington, Oregon, and California must reflect climatic changes in this region since deglaciation. An increase in summer moisture deficits is assumed to be largely responsible for this trend.
6. Though a majority of the Cladoniaceae are probably now at distributional equilibrium, a few species -- e.g., Cladina stellaris and C. trassii -- appear still to be extending their ranges southward from refugia north of the Cordilleran Icesheet.

References:

Geiser, L.H., K.L. Dillman, C.C. Derr & M.C. Stensvold. 1994.

Lichens of southeastern Alaska. United States Department of Agriculture, Forest Service. Alaska Region, Juneau, Alaska. R10- TP-45.

Goward, T. & T. Ahti. 1997.

Notes on the distributional ecology of the Cladoniaceae (lichenized Ascomycetes) in temperate and boreal western North America. Journal of the Hattori Botanical Laboratory 82: 143-155.

Hammer, S. 1995.

A synopsis of the genus Cladonia in the northwestern United States. The Bryologist 98: 1-28.

Thomson, J.W. 1984.

American Arctic Lichens 1. The macrolichens. Columbia University Press, New York, New York.