Coleogyne

Torrey

Proc. Amer. Assoc. Advancem. Sci. 4: 192. 1851.

Common names: Blackbrush
Endemic
Etymology: Greek koleos, sheath, and gyne, female, alluding to thin staminal tubelike sheath surrounding ovary and style
Treatment appears in FNA Volume 9. Treatment on page 390. Mentioned on page 21, 386, 387.

Shrubs, 2–6 (–10) dm, herbage strigose, with appressed medifixed hairs. Stems 15–150, stiffly erect; bark dark russet, becoming gray, striate; long-shoots divaricately and oppositely branched, short-shoots present; unarmed (stiff dead branches resembling thorns). Leaves persistent (drought deciduous), cauline, opposite and clustered on short-shoots; stipules persistent on distal leaf-base margins, deltate-lanceolate, margins entire; petiole obscure; blade oblanceolate-spatulate, 0.6–1.2 cm, thickened, leathery, margins thick, rounded (not revolute), entire. Inflorescences terminal on long and short-shoot spurs, flowers solitary; bracts present, reduced, leaflike. Pedicels reduced. Flowers 11–14 mm diam.; epicalyx bractlets 0; hypanthium campanulate, 1–2 mm; sepals 4 (rarely 5), weakly spreading, abaxially yellow, outer narrowly ovate, inner broadly ovate, margins thin; petals usually 0, infrequently 1–4 (or 5) on scattered flowers, caducous, translucent yellow, spatulate; stamens (16–) 20–25 (–30), equal to sepals; torus extending into tubelike sheath surrounding ovary and proximal style (interior sericeous, exterior bearing some stamens); carpels 1 (rarely 2), glabrous except at style base, styles lateral, exserted beyond sheath, sericeous most of length; ovule 1, lateral. Fruits achenes, 1 (–2), brown, ovoid-reniform, distally narrower, 5.3–5.8 mm, shiny, glabrous; hypanthium persistent; sepals persistent, ascending. x = 8.

Distribution

sw United States

Discussion

Species 1.

Coleogyne is a xeromorphic desert shrub with floral features unusual within Rosaceae: a peculiar sheathlike torus surrounds the carpel and most of the style that bears some of the stamens, four sepals, and petals commonly absent but the inner sepal surface strongly yellow; vegetatively, Coleogyne is further distinguished by its opposite leaves and uniformly oriented medifixed trichomes. The single-ovuled, solitary ovary has a lateral style, suggesting relationship with multi-ovuled ancestors. Molecular data support relationships in the Kerrieae in subfam. Amygdaloideae (D. Potter et al. 2007).

Selected References

None.

... more about "Coleogyne"
James Henrickson +  and Bruce D. Parfitt† +
Torrey +
gray +  and dark russet +
compound +  and simple +
opposite +  and alternate +
oblanceolate-spatulate +
0.6 cm6 mm <br />0.006 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
reduced +
free +  and distinct +
Blackbrush +
sw United States +
not +  and aggregated +
Greek koleos, sheath, and gyne, female, alluding to thin staminal tubelike sheath surrounding ovary and style +
1.1 cm11 mm <br />0.011 m <br /> (1.4 cm14 mm <br />0.014 m <br />) +
unisexual +  and bisexual +
not +  and aggregated +
not +  and aggregated +
ovoid-reniform +
0.53 cm5.3 mm <br />0.0053 m <br /> (0.58 cm5.8 mm <br />0.0058 m <br />) +
not +  and aggregated +
medifixed +
0.1 cm1 mm <br />0.001 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
crassinucellate +
opposite +  and alternate +
persistent +
thin +  and thick +
inferior +  and superior +
biseriate +  and clustered +
0 (?) +  and 4 (?) +
free +  and distinct +
1 +  and 4 +
adnate +, free +, connate +  and distinct +
Proc. Amer. Assoc. Advancem. Sci. +
not arillate +
persistent +
free +  and distinct +
ascending +  and spreading +
inner +  and outer +
tubelike +
free +  and distinct +
branched +  and simple +
15 +  and 150 +
persistent +
distinct +
sericeous +
not elongate +
Coleogyne +
Rosaceae tribe Kerrieae +
inconspicuous +