Lasianthaea fruticosa var. occidentalis K.M.Becker
-
Authority
Becker, Kenneth M. 1979. A monograph of the genus Lasianthaea (Asteraceae). Mem. New York Bot. Gard. 31 (2): 1-64.
-
Family
Asteraceae
-
Scientific Name
-
Description
Species Description - Small shrubs 0.5-2 high; young branches usuaHy spreading-hispidulous to hirsute. Leaves with petiole 2-12 mm long; blade usually firm, lance-ovate to ovate, or occasionally lanceolate, 4-12 cm long, 1-5.5(-6) cm wide, hispid and hispidulous below, especially along veins, venation conspicuous below, triplinerved. Inflorescence 3-13-headed. Peduncles (0.2-)0.8-5.0 cm long, slender; heads 1.5-2.5 cm wide across extended rays. Involucre broadly campanulate, 0.6-1.0 cm high, 0.6-1.1 cm wide, phyllaries usually subequal, occasionally graduated in 2-3 series. Outer phyllaries conspicuously reticulate-veined and sometimes spreading above, ovate-oblong or lance-oblong in outHne, usually narrowed near middle, 5-7 mm long, 2-3 mm wide, inner phyHaries 6-7.5 mm long, 1.5-3 mm wide. Rays 7 or 8, lamina 7.5-9.5 mm long, 4.5-5 mm wide. Disc florets 17-30, 6-7.5 mm long. Disc achenes with body 3.0-3.7 mm long, 0.9-1.8 mm wide, awns 2.5-4 mm long, usually not exserted or exserted to 1 mm from ripe heads. Ray achenes with body 1.5-3.3 mm long, 1.8-2.0 mm wide.
Distribution and Ecology - Hills and canyons in pine-oak forest. Northern Sierra Madre Occidental in Mexico (Map 1), at altitudes from 1100-2000 m . Blooming August to October (-December).
-
Discussion
Lasianthaea fruticosa (L.) K. Becker var. occidentalis K. Becker, var. nov.; differt a var. fruticosa phyllariis extimis insuper dilatatis et conspicue reticulato-venosis, pubescentia plerumque effusa, a var. alamosana aristis plerumque non exsertis (ad 1 mm) et foliis firmis.
Lasianthaea fruticosa var. occidentalis is restricted in range to the northern Sierra Madre Occidental (Map 1). It is known from relatively few collections, perhaps reflecting the fact that the area is poorly collected. It is typically a small shrub with long internodes, conspicuously veined leaves, and outer phyllaries which are more or less ampliated above, green, and conspicuously reticulate-veiny. This variety has a relatively strong tendency towards graduation of phyllaries. Variety occidentalis comes closest, both geographically and morphologically, to varieties fasciculata and alamosana.
Type: MEXICO: Chihuahua: Near Seven Star Mine, ak. 8000 ft. 29 Aug 1899, Townsend & Barber 384 (holotype: G H , isotypes: F, G(2), K, MEXU, MICH, MO, NY, P(2), POM, UC, US).