Name
Acaciella rosei (Standl.) Britton & Rose, N. Amer. Fl. 23: 105. 1928.
Rico Arce & BachmanAnales del Jardín Botánico de MadridVol. 63(2): 189-244July-December 2006
Synonymy and types
Acacia rosei Standl., Contr. U.S. Natl. Herb. 20: 187. 1919. Type: Mexico: Sinaloa, Mazatlán vicinity, 30-III-1910, Rose, Standley & Russell 13673 (holotype, US!; isotype, NY!).
Acaciella ortegae Britton & Rose, N. Amer. Fl. 23: 106. 1928. Type: Mexico: Sinaloa, Mazatlán, J. González Ortega 6501 (holotype, US!; isotypes, K!, MEXU!, NY!).
Acacia mazatlana M.E. Jones, Contr. West. Bot. 15: 141. 1929. Type: Mexico: Sinaloa; Mazatlán, M.E. Jones 22430 (holotype, POM; isotype, GH!).
Formal description
Shrub to 5 m tall, sparsely hirtellous-pilose. Stipules 2-2.5 mm long, c. 1 mm wide, pubescent, fugacious. Leaves 15 cm long; petiole 2.4(3) cm long, glabrous; rachis 2-3 cm long, glabrous, with 1-2 pairs of pinnae; pinnae 3.5-7.5 cm long; paraphyllidia 2.5 mm long, fugacious; leaflets 2-3(4) pairs per pinna, 3-6.5 × (0.9)1.2-3 cm, elliptic to widely elliptic, base and apex acute, brochidodromous venation well marked on both surfaces, glabrous above, sparsely pubescent only along the veins on the under surface, coriaceous. Inflorescence comprising clusters of 2-3 racemes in terminal panicles, less frequently axillary, main rachis 7-16 cm long, slightly hirsute; peduncles 0.8-1.8 cm long; glabrous or nearly so, without pearl glands; 2 inflorescence bracts on the peduncle, one near the base, 5 mm long, linear-triangular, pubescent, fugacious, another higher up the peduncle close to the raceme, 0.75 mm long, lanceolate, usually glabrous or with only a very few pilose hairs; floral bract 0.7 mm long, slightly hirtellous, clavate, fugacious, very conspicuous when the inflorescence is immature; pedicels 0.8- 1mm long, glabrous; flowers white, in short capitulum- like racemes 12-14 mm in diam. at anthesis. Calyx 0.5 mm long, the lobes 5-lobed, less than ¼ the length of the whole calyx, calyx almost truncate, almost glabrous. Corolla 2.2 mm long, 5-lobed, the lobes to more than half the whole corolla length, glabrous. Stamens 4-5 mm long. Ovary 1.5 mm long, glabrous, short-stipitate, the stipe shorter than the ovary; basal nectary 0.25 mm high. Legume 5-5.8 × 1.4 × 0.2-0.25 cm, flat, straight, dehiscent; valves chartaceous, conspicuously reticulate, glabrous, acute at the base and apex; stipe 1.3 cm long; beak to 3 mm long. Seeds 8 per fruit.
Distribution
Mexico north and central: Colima, Jalisco, Sinaloa and Sonora.
Additional info
Habitat. Seasonally dry forest; often in association with Bursera; on limestone and clay-loam soil. Alt. 0- 600 m.
Flowering time
Flowering August to March, fruiting October to March.
Representative specimens
MEXICO:
Colima:
- Vicinity of Manzanillo, 19º 02' N, 104º 19' W, 28-XI-1925, Ferris, Roxana 6085 (NY);
- 10 m SE of Colima, 400 m, 5-XII-1959, McVaugh 1461 (MEXU);
- 19º 03' N, 104º 17' W, 94 m, 21-X-1910, Orcutt, C.R. 4460 (MEXU).
Jalisco:
- Arroyo Cuixmala, Cumbres 1, 19º 31' N, 104º 56' W, 300 m, 5-XI-1991, Lott, E.J. 4152 (K, MCS, MEXU);
- 25 km NW of Río San Nicolás and 20 SE of Tomatlán, 19º 50' N, 105º 23' W, 10-XII-1970, McVaugh 25295 (MEXU, NY).
Sinaloa:
- NE de Huajote, 25º 31' N, 107º 37', 250 m, 9-X-1992, González E., A. s.n. (MEXU);
- La Bajada, 25º 55' N, 109º 00' W, 300 m,-XI- 1922, González Ortega, J. 554 (MEXU);
- Mazatlán, 23º 13' N, 106º 25' W, III-1931, González Ortega, J. 6740 (G, MEXU, MO).