Home Brassicaceae
Name Search
Species List
Boechera horizontalis (Greene) Windham & Al-Shehbaz Search in The Plant ListSearch in IPNISearch in Australian Plant Name IndexSearch in NYBG Virtual HerbariumSearch in Muséum national d'Histoire naturelleSearch in Type Specimen Register of the U.S. National HerbariumSearch in Virtual Herbaria AustriaSearch in JSTOR Plant ScienceSearch in SEINetSearch in African Plants Database at Geneva Botanical GardenSearch in Flora do Brasil 2020Search in Reflora - Virtual HerbariumSearch in Living Collections Decrease font Increase font Restore font

Published In: Harvard Papers in Botany 11(2): 266. 2007. (Harvard Pap. Bot.) Name publication detail

Project Name Data (Last Modified On 7/21/2009)

Export To PDF Export To Word

46. Boechera horizontalis (Greene) Windham & Al-Shehbaz, Harvard Pap. Bot. 11: 266. 2007; Arabis horizontalis Greene, Leafl. Bot. Observ. Crit. 2: 74. 1910; A. suffrutescens S. Watson var. horizontalis (Greene) Rollins, Res. Stud. State Coll. Wash. 4: 50. 1936. TYPE: United States, Oregon, Oregon. Klamath Co.: Crater Lake, along the trail to the boat landing, 1 Aug 1897, Frederick V. Coville & Elmer I. Applegate 334 (holotype, US!; isotypes, RM!, US!).

     Plants long-lived, cespitose perennials, with woody caudices, lacking crowded, persistent leaf bases; apomictic, with spheroid pollen. Stems usually 1 per caudex branch, somewhat elevated on woody bases or arising near ground surface from center of basal rosettes, 1–3.5 dm, lower parts with few short-stalked, 3–6-rayed trichomes 0.1–0.3 mm, upper parts glabrous. Leaves at stem bases narrowly oblanceolate, 1–5 mm wide, entire, ciliate near petiole bases with simple trichomes to 0.4 mm, blade surfaces densely pubescent with short-stalked, 3–6-rayed trichomes 0.1–0.3 mm; cauline leaves 3–13, often concealing stem proximally, the uppermost glabrous, with auricles 0.5–1.5 mm. Inflorescences mostly unbranched, 5–32-flowered; fruiting pedicels 4–11 mm, horizontal to descending, straight or slightly curved downward, glabrous. Flowers divaricate-ascending at anthesis; sepals pubescent; petals lavender to purple, 5–6 ´ 1.5–2.0 mm, glabrous; ovules 40–54 per fruit. Fruits 2–4 cm ´ 2–3 mm, horizontal or descending, not appressed to rachises, secund, straight, with slight undulate (non-parallel) edges, glabrous; style 0.2–0.5 mm. Seeds uniseriate, 2.0–2.5 ´ 1.7–2.0 mm; wing continuous, 0.5–1.0 mm wide.

Flowering: Jul–Aug.

Habitat: dry pumice slopes.

Distribution: United States (Oregon/vicinity of Crater Lake).

Reproductive mode: apomictic triploid.


© 2018 Missouri Botanical Garden - 4344 Shaw Boulevard - Saint Louis, Missouri 63110