Perennials, 8-25 cm (rhizomes branched, 1-10 mm diam.); herbage lemon-scented or spicy-scented. Stems ascending to erect (very leafy), glabrous. Leaves linear to linear-oblanceolate, 10-55 × 1-3 mm, margins with 1-4 pairs of setae, faces glabrous (conspicuously dotted on margins with round oil-glands 0.3-0.5 mm). Heads borne singly. Peduncles (30-)50-160 mm. Involucres campanulate. Phyllaries distinct, linear, linear-oblanceolate, or linear-elliptic, 5-8 × 0.7-2 mm (dotted with 1-3, swollen, subterminal oil-glands 0.3-0.4 mm plus 1-3 pairs of narrow, submarginal oil-glands). Ray florets (8-)13(-15); corollas 8-12 mm. Disc florets 25-50; corollas 4-6 mm (2-lipped). Cypselae 2.5-4.5 mm, strigillose (hairs tips acute or blunt); ray pappi of 1-2 awns 3-3.5 mm; disc pappi of 2-30 unequal bristles 3-5 mm. 2n = 24, 48. Flowering Apr-Nov. Grasslands, oak-juniper-mesquite woodlands; 900-1700 m; Ariz., N.Mex.; Mexico (Chihuahua, Durango, Sonora). Pectis longipes has been listed from Texas in floras; I have seen no collections from that state.
Pectis longipes comprises two cytological races. Diploid, spicy-scented plants occur throughout the range. In southern Arizona, the diploid race is broadly sympatric but locally allopatric with a tetraploid, lemon-scented race. The tetraploid race is nested within the range of the diploids. The races are easily separable by odor, and although they are very similar morphologically, they can be separated also by statistically significant differences in floral dimensions and pollen size (M. A. Luckow 1983). Based upon those minute differences, the type collection is diploid. Because the races are so similar morphologically and because so many of the specimens of P. longipes in herbaria bear no indication of odor, I chose not to give the cytological races formal recognition.
FNA 2006, Wiggins 1964, Kearney and Peebles 1969
Duration: Perennial Nativity: Native Lifeform: Subshrub General: Perennials with slender caespitose caudex with many decumbent branches 5-25 cm long, closely leafy below, glabrous, ascending at tips, striate and often reddish tinged, with lemon-scented or spicy-scented herbage. Leaves: Linear to linear-oblanceolate, 10-55 mm long by 1-3 mm wide, with 1-4 pairs of bristles, thickish, mucronate at apex, faintly to strongly revolute, with margins conspicuously dotted with round oil-glands 0.3-0.5 mm. Flowers: Heads borne singly at end of branches and in upper axils on peduncles 50-160 mm long; involucres campanulate with distinct phyllaries, linear, linear-oblanceolate, or linear-elliptic, 5-8 mm long by 0.7-2 mm wide, dotted with 1-3, swollen, subterminal oil glands 0.3-0.4 mm; yellow ray florets 12-15, with corollas 8-12 mm; disc florets 25-50, with 2-lipped corollas 4-6 mm long. Fruits: Cypselae 2.5-4.5 mm, stiff hairs with hair tips acute or blunt, ray pappus of 1-2 awns, 3-3.5 mm and disc pappus of 2-30 unequal bristles, 3-5 mm long. Ecology: Found on rocky and gravelly soils from 3,000-5,500 ft (914-1676 m); flowers April-November. Notes: FNA notes that the tetraploid race of Pectis is lemon-scented and that the diploid races are separable by the odor characteristic, but also notes that the diploid race is sympatric, but locally allopatric with this tetraploid race. Notably, the Pectis have C4 photosynthetic pathways which accounts for why they inhabit such hot, dry sites. Ethnobotany: Unknown Etymology: Pectis is from the Greek pecteo, to comb , while longipes means long-stalked. Synonyms: None Editor: SBuckley, 2010
Citation: The vPlants Project. vPlants: A Virtual Herbarium of the Chicago Region. http://www.vplants.org
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