Philadelphus argyrocalyx (Silvercup Philadelphus)

Philadelphus argyrocalyx (Silvercup Philadelphus)

Photograph by Robert Sivinski (2000)
Family
HYDRANGEACEAE
Scientific Name with Author

Philadelphus microphyllus var. argyrocalyx (Wooton) Henrickson

Synonyms

PHILADELPHUS ARGYROCALYX WOOTON; PHILADELPHUS SERPYLLIFOLIUS VAR. ARGYROCALYX (WOOTON) M.E. JONES; PHILADELPHUS ELLIPTICUS RYDBERG; PHILADELPHUS MICROPHYLLUS SUBSP. ARGYROCALYX (WOOTON) C.L. HITCHCOCK; PHILADELPHUS WOOTONII HU

Common Name
Silvercup Philadelphus
Rare Plant Conservation Scorecard Summary
Overall Conservation Status Documented Threats Actions Needed
UNDER CONSERVED

No Information

Study effects of forest fire


County Map
Counties
Description

Erect shrub 1-2 m tall; leaves opposite, ovate, ovate-lanceolate or narrowly elliptic, margins entire, 10-35 mm long, 4-17 mm wide, glabrous or glabrescent above, sparsely villous hairy below, petiole about 2 mm long; flowers usually solitary (rarely 2 or 3) at the end of a short shoot 2-4 cm long with 2-4 pairs of leaves; calyx tube forming a cup (hypanthium); pedicels, hypanthia and sepals covered in dense tomentum of short, woolly hairs and longer, straight hairs; sepals 4; petals 4, white, 1.2-2.2 cm long, 0.7-1.8 cm wide; corolla cruciform, 2.2-4.2 cm across; stamens about 55, filaments fused into bundles; style and hypanthium disk glabrous; each seed long-tailed. Flowers June to August.

Similar Species

The hypanthium and sepals of Philadelphus microphyllus var. microphyllus are glabrous or only sparsely hairy at the base.

Distribution

New Mexico, southern Lincoln and northern Otero counties, Capitan, Sacramento, and White mountains.

Habitat

Mountain slopes of usually sedimentary rock in piƱon-juniper woodland and lower montane coniferous forest; 2,100-2,600 m (6,900-8,500 ft).

Remarks

Endemic to the mountains of south-central New Mexico, but relatively common within this limited range. It is a handsome shrub with potential for ornamental use.

Conservation Considerations

This plant is not significantly threatened by the land uses within its habitats. Its response to forest fire has not been studied.

Important Literature

Hu, S. 1954. A monograph of the genus Philadelphus. Journal of the Arnold Arboretum 37:15-90.

Frazier, C.K. 1999. A taxonomic study of Philadelphus (Hydrangeaceae) as it occurs in New Mexico. The New Mexico Botanist 13:1-6.

Henrickson, J. 2007. New combinations in Philadelphus (Philadelphaceae). Journal of the Botanical Research Institute of Texas 1(2):901.

Information Compiled By
Robert Sivinski 1999; last updated 2008

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