Ipomopsis congesta ssp. matthewii

Ipomopsis congesta ssp. matthewii

Family
POLEMONIACEAE
Scientific Name with Author

Ipomopsis congesta ssp. matthewii J.M. Porter

Common Name
None

Counties
Description

Porter, 2011: Polycarpic perennials, bearing a branching, subterranean, woody caudex, sometimes taprooted when
young, plants sometimes subshrubby at the base. Stems 1–20, decumbent, ascending or erect, simple or with
up to 5 or more branches, 4–30 cm tall, with both glandular and eglandular trichomes, usually densely
floccose. Leaves mostly cauline on each stem at flowering, 8–30 mm long, lower leaves linear and entire 0.8–
1.2 mm wide, upper leaves pinnatifid, with (2–)3–7 narrow segments, the terminal lobe, 0.7–1 mm wide,
trichomes glandular and eglandular, more or less white villous or floccose, usually restricted to the adaxial
veins. Inflorescence solitary or paniculately arranged heads, flowers in dense, capitate, cymose heads, 14–
25(–27) mm broad, flowers sessile or subsessile, inconspicuously bracteate, bracts 2.5–6(–10) mm long,
simple, outermost trifid to 5-lobed, with 1–2 flowers subtended by a bract. Calyx usually 3.5–5.5 mm long,
free portion of the lobes 1.0–2.5 mm long, mucronate or shortly aristate, the margins hyaline, densely villous,
the fused portion (tube) sparsely glandular puberulent, the green, herbaceous costae alternating with a narrow
hyaline region. Corolla salverform, cream-white, 4.5–7.5 mm long; the tube 3.5–5(–6) mm long, only slightly,
if at all surpassing the calyx, external corolla glabrous, rarely with a few glandular trichomes, internal tube
with glandular trichomes (or papillae) along the more proximal staminal vasculature; lobes spreading, (1.5–
)2–3 mm long, elliptic-ovate to elliptic-oblong, rounded to acute at the apex. Filaments diverging from the
corolla tube at the sinuses of the lobes, slightly curved, 0.8–2(–3) mm long, the anthers 0.5–1.5 mm long,
exserted beyond the orifice of the corolla, pollen cream-white. Style reaching the anthers and slightly
exserted, proximal portion sparsely glandular, the trichomes sometimes to 1 mm long. Ovary ovoid, bearing a
few glandular trichomes at the apex, locules 3, 1 ovule per locule. Fruit a loculicidal capsule, 2.5–3.5 mm
long, dehiscing from the apex, valves usually remaining fused at the base, with 1 seed per locule, often with
some locules empty. Seeds 2–2.5 mm long, 0.6–1 mm wide, ellipsoid-fusiform, wingless, light brown to pale
chestnut, funicular scar linear, elongate, surface irregular, becoming mucilaginous when wetted, embryo
green, slightly curved, often visible within the seed.

Flowering begins in late April and generally continues through late June or early July.
Exceptionally, flowering may continue into September. Fruiting begins in mid-May and lasts through August
or rarely into September.

Similar Species

Most similar to I. c. subsp. congesta, I. c. subsp. matthewii differs in generally having a more suffrutescent base, cream-white flowers and pollen, and displaying heteroblastic leaf variation (early leaf production of simple, entire, linear leaves, later production of pinnatifid leaves with long, linear segments).

Distribution

Populations are small, and scattered across the Four Corners region over a wide area from Montrose and Archuleta Counties, Colorado, to San Juan County, Utah, south to Navajo and Apache Counties, Arizona, and San Juan County, New Mexico. This subspecies ranges from its southern-most location on the Rio Puerco breaks in eastern Sandoval Co., NM 230 miles northwest to western foot of the La Sal Mountains in northeastern San Juan Co., UT. The width of that range is greatest (120 miles) from La Boca in La Plata Co., Colorado west to the vicinity of Bluff in San Juan Co., UT. It is sporadically distributed across this range, but not uncommon in suitable habitats (personal observations) such as slickrock mesa formations on the Navajo and Mountain Ute lands straddling the NM/CO border. Herbarium specimens are fairly abundant with >30 each for AZ and NM, and 15-20 each for CO and UT.

Habitat

This subspecies occurs in arid habitats, primarily associated with pinyon-juniper woodland. However it may be found in sagebrush flats (often with scattered pinyon-juniper) or in desert scrub vegetations, where it may be found in badlands. Rarely, it has also been found in ponderosa pine-Gambel oak woodlands. Most frequently it is found in sandy pockets of sandstone outcrops,ledges, and ridge tops. It can also occur on sandy soils or clay soils, particularly if covered by alluvial or pediment gravels (Porter, 2011). Elevation ranges from 1675-2400 m (5500-8000 ft).

Remarks

The specific epithet, matthewii, honors Matthew Heil, energetic field botanist of the Four Corners region, whose life was tragically cut short.

Conservation Considerations

In spite of the new taxonomic recognition of Ipomopsis congesta subsp. matthewii, this subspecies is neither rare nor in need of specific conservation effort. It occurs over a wide area, from Montrose and Archuleta Counties, Colorado, to San Juan County, Utah, south to Navajo and Apache Counties, Arizona, and San Juan County, New Mexico. Even so, this is not a particularly common race, occurring in small populations, scattered across the region.

Most of the region of this subspecies has been, or is actively being developed for natural gas and oil, and coal mining to a small extent. Some populations have likely been diminished but are still widely distributed around these impacts.

Important Literature

Porter, J.M. 2011. Two new Aliciella species and a new subspecies in Ipomopsis (Polemoniaceae) from the western United States of America. Phytotaxa 15: 15-25.

Information Compiled By
Bob Sivinski, Daniela Roth 2020

For distribution maps and more information, visit Natural Heritage New Mexico