Astragalus gilviflorus

Crataegus douglasii

Douglas Hawthorn

Leaf Bottom Close-Up

Centre Block, Cypress Hills Interprovincial Park
19-June-2013

Note that Flora of Alberta requires that the leaves be nearly glabrous beneath. This specimen has a few scattered hairs, particularly on the veins.

Crataegus is a difficult genus, characterized by hybridization, polyploidy, and apomixis. In many cases it is better to describe species complexes rather than individual species. Nevertheless, I believe this specimen possesses enough characteristics associated with C. douglasii to ascribe it to this species.

Douglasii: Answers to key questions in Budd's Flora and Flora of Alberta leading to this species.

thorns stout and short; NOT [thorns long]

leaves nearly glabrous beneath, more or less pubescent above; NOT [leaves pubescent beneath, at least on the veins]

sepals short, triangular, acute but not attenuate; NOT [sepals attenuate, long-pointed] (BF)

sepals ovate; NOT [sepals lanceolate, acuminate] (FOA)

sepals hairy above

sepals often without glands; NOT [sepals glandular-margined]

fruit black or deep purple when ripe; NOT [fruit red or red-purple]

nutlets pitted

Crataegus Answers to key questions in Budd's Flora and Flora of Alberta leading to this genus.

shrubs or trees; NOT [herbs, or with a woody base and otherwise herbaceous]

plants taller; NOT [creeping dwarf shrubs]

stems with stout thorns; NOT [stems not thorny]

spines never leafy; NOT [spines leafy in the first year, leafless thereafter]

leaves simple; NOT [leaves compound or lobed]

leaves mostly incised-toothed or lobed; NOT [leaves entire to toothed]

flowers usually more numerous; NOT [flowers solitary on a long peduncle]

NOT [flowers in broad compound corymbs]

ovary inferior; NOT [ovary or ovaries superior]

ovary enclosed in and adnate to the hypanthium; NOT [hypanthium shaped like a saucer, cup or urn and free from the ovary]

fruit a pome but often berry-like

Rosaceae: Answers to key questions in Budd's Flora leading to this family.

herbs; NOT [shrubs or trees]

plants terrestrial or semiaquatic; NOT [plants aquatic, leaves submerged or floating]

plants NOT with colored milky juice

plants with more than one normal leaf

some or all leaves alternate; NOT [leaves opposite, whorled, or basal]

leaves with stipules; NOT [leaves without stipules, or having glands]

flowers with two floral rings, and with each petal distinct from the others

flowers regular in shape; NOT [flowers irregular in shape]

calyx regular; NOT [calyx irregular, some sepals smaller than others]

stamens usually separate or partly so, not in a column; NOT [stamens numerous, united into a column]

ovary of one or more carpels, either separate or enclosed by a fleshy receptacle; NOT [ovary of 5 united carpels]