12.  Marina orcuttii (Watson) Barneby

(Plate XIV)

Slender, decumbent, perennial herbs from a woody taproot and short caudex, strigulose nearly throughout with fine, appressed hairs up to 0.2-0.3 mm long, the simple or commonly (subbasally or distally) few-branched, pallid or pink-tinged, smooth, terete, eglandular stems 1-3.5 dm long, the foliage greenish-cinereous, the folded leaflets lineolate both sides, pubescent and gland-tipped beneath, glabrous above; leaf-spurs 0.3-0.6 mm long; stipules castaneous, becoming dry and fragile, subulate to triangular-subulate, 0.4-1.3 mm long; intrapetiolular gland 0; post-petiolular glands very small, sometimes impressed or obsolete; main cauline leaves (the lower drought-deciduous) 8-30 mm long, shortly petioled, with (3) 4-12 pairs of obovate to oblanceolate, obtuse leaflets (1.5) 2-5 mm long, charged dorsally around the margins with a row of small, sometimes scarcely visible glands; peduncles leaf-opposed, slender, incurved distally, (1) 1.5-3.5 cm long; racemes moderately dense, ovoid becoming oblong, without petals 8-9 mm diam, the flowers early nodding, the axis at length (0.5) 1-2.7 cm long; bracts herbaceous early becoming papery and deciduous before anthesis, lance-ovate beyond the cuneate base, 1.8-2.5 mm long, the margins gland-spurred; pedicels 0-.2-0.4 mm long; calyx 4.2-5 mm long, hirsutulous with spreading-ascending, straight hairs up to 0.45-0.6 mm long, the tube 1.1-22 mm long, its membranous intervals charged with a single row of small glands extending well beyond the sinuses of the teeth, the plane, herbaceous teeth ± unequal, the lanceolate dorsal one longest, 2.1-3.1 mm long, the ventral pair slightly to decidedly shorter, 2-2.3 mm long; petals bicolored, the banner blade margined with lilac, pale and gland- sprinkled medially, the inner petals pale in outer half, lilac-striped in inner half, eglandular; banner 2.6-3.3 mm long, the claw 1.6-1.9 mm, the reniform to transversely oblong-cordate blade 1.3-1.8 mm long, 2.2-2.6 mm wide; wings 2.9-3.7 mm long, the claw 0.5-1.6 mm, the blade 2.6-3 mm long, 1.3-1.8 mm wide; keel 4.9-5.5 mm long, the claws 1.4-1.8 mm, the blades 3.6-4.1 mm long, 2A-2.1 mm wide; androecium 10-merous, 4.5-5.2 mm long, the longer filaments free for 1.6-1.9 mm, the connective gland-tipped, the pinkish anthers 0.5-0.8 mm long; pod ± 3 mm long, essentially as in M. calycosa.

This rare species, endemic to three (possibly four) mountain ranges rising from the western margins of the Sonoran Desert, is the only marina known from this region that is characterized by nodding flowers. It is closely related to M. calycosa of the northern Sierra Madre Occidental, from which it differs principally in its superficial root-crown, smaller flowers, and evidently though sometimes only faintly gland-sprinkled dorsal face of the leaflets. It has been confused with M. peninsularis (as by Bullock, 1939, p. 197, who cited a paratype at K) which has flowers of about the same size but hirsutulous, prominently glandular stems, ascending flowers, and magenta-violet petals, and is found at much lower elevations on the desert floor.

The known range of M. orcuttii is highly restricted and discontinuous, with two small foci in California and in Sierra Juarez close below the boundary, the third in Sierra de las Palmas, distant about 680 km air-line southeastward down the peninsula. The populations in these mutually remote localities are slightly differentiated and seem to deserve taxonomic recognition.