Bromus pseudolaevipes Wagnon (1950: 64)

Saarela, Jeffery M., Peterson, Paul M. & Valdés-Reyna, Jesus, 2014, A taxonomic revision of Bromus (Poaceae: Pooideae: Bromeae) in México and Central America, Phytotaxa 185 (1), pp. 1-147 : 110-112

18. Bromus pseudolaevipes Wagnon (1950: 64) . Figs. 58 , 59 .

Bromopsis pseudolaevipes (Wagnon) Holub (1973: 168) . Type:— UNITED STATES OF AMERICA. Cultivated: grown at the Botanical Gardens, University of Michigan, Ann Arbor, 2 June 1948, H.K. Wagnon 1507; original source from seed reproduced at the Univeristy of California, Berkeley, originally collected by G. L . Stebbins Jr. 2862 along the Ridge Route Wof Castaic , Los Angeles Co. (holotype MICH-1108615 !, isotypes CAS-0027837!, MO-1600838 !) .

Plants perennial, not rhizomatous. Culms 60–125 cm tall, 2–4 mm wide at base, erect or ascending, pubescent below inflorescences; nodes 2–5, pubescent. Leaf sheaths glabrous or densely pilose, hairs up to 1.2 mm long; 110 Phytotaxa 185 (1) © 2014 Magnolia Press

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Phytotaxa 185 (1) © 2014 Magnolia Press 111 auricles usually present on the lower leaves, sometimes absent; ligules 0.4–1(–2) mm long, glabrous or pubescent; blades up to 35 cm × 2–9 mm, flat, adaxial and abaxial surfaces pubescent throughout or on margins, hairs up to 0.6 mm long, rarely glabrous, margins serrulate. Panicles 7.5–20 cm × up to 14 mm, open, nodding, branches erect to ascending, 0.3–4 cm long, longer or shorter than spikelets, pubescent, 2–3(–4) spikelets per branch. Spikelets 1.5–3.5 cm long, 4–10-flowered, elliptic to lanceolate, terete to moderately laterally compressed; glumes scabrous or pubescent, hairs up to 0.3 mm long, margins hyaline, midnerves pubescent; lower glumes 4–7 mm long, lanceolate to oblong, 3-nerved, green along and between the nerves, apices acute; upper glumes 6–9 mm long, oblong-ovate, 5-nerved, green along and between the nerves, apices acute to obtuse; lemmas 10–12.5 mm long, elliptic to lanceolate, rounded over the backs, apices obtuse to truncate, 7-nerved, green along and between the nerves, pubescent throughout or hairs restricted to margins, hairs up to 0.5 mm long; awns 2–5.5 mm long, inserted up to 0.5 mm below lemma apex, straight; paleas shorter and narrower than the lemmas, backs pubescent, keels ciliate, cilia up to 0.3 mm long; anthers 3.5–5.5 mm; caryopses 8−10 mm long, dark brown to black. 2 n = 14 ( Wagnon 1950).

Distribution: —Native. In México B. pseudolaevipes is known from northern Baja California ( Fig. 60 ). We have seen only a single specimen of the taxon from México. Gould & Moran (1981) also reported B. pseudolaevipes from Baja California. They noted the specimen they cited (Beetle M-2696, near and Eof Rosarito; not seen) to be "atypical in having blades to 14 mm broad" ( Gould & Moran 1981: 30), which is outside the range of variation known for this species ( Pavlick & Anderton 2007, Saarela & Peterson 2012). Bromus pseudolaevipes has been considered to be endemic to California ( Wagnon 1952, Peterson & Soreng 2007), but it is not, given its occurrence in Baja California. Pavlick & Anderton (2007) state that B. pseudolaevipes is not known from México, which is incorrect. In the United States it occurs in the Coastal ranges of California ( Pavlick & Anderton 2007, Saarela & Peterson 2012).

Ecology:— Shaded or semi-shaded sites in chaparral, coastal sage scrub and open woodland; associated with Arctostaphylos , Ceanothus , Rhus and Eriogonum fasciculatum Bentham (1836: 411) Elevation : 1350 min México.

Common Names: —Woodland brome (English).

Comments: — Bromus pseudolaevipes is distinguished by its five-nerved upper glumes. It is the only species in sect. Bromopsis in México with this character.

Specimen Examined:— MÉXICO. Baja California: Sierra San Pedro Martír , 1.1 mi SW of Mike's Sky Ranch on road towards Meling Ranch, 1350 m, 31.109°N, 115.6508°W, 25 September 2000, P. M . Peterson & J . Cayouette 15211 ( CAN, US).

112 Phytotaxa 185 (1) © 2014 Magnolia Press

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Figures

FIGURE 58. Bromus pseudolaevipes. A. Ligule and auricles. B. Ligule and leaf sheath. C. Inflorescence. D. Lemma. E. Spikelet. Illustration by C.T. Roché, reproduced from Barkworth et al. (2007) with permission.

FIGURE 59. Bromus pseudolaevipes. Peterson & Cayouette 15211 (CAN, unmounted).

FIGURE 60. Geographical distribution of Bromus pseudolaevipes in México.