Dalea jaliscana A. E. Estrada & Villarreal, 2016

Castillón, Eduardo Estrada & Quintanilla, José Ángel Villarreal, 2016, A new species of Dalea (Fabaceae, Faboideae) from Jalisco, México, Phytotaxa 246 (1), pp. 90-92 : 90-92

Dalea jaliscana A. E. Estrada & Villarreal , sp. nov. ( Fig. 1 A–L )

Dalea jaliscana is morphologically similar to Dalea sericea but differs in pair number, size, shape and pubescence of the leaflets; stipule size; intra-petiolular gland shape; size and diameter of the spikes without flowers; calyx size; flower color and size of the petals.

Type:— MEXICO. Jalisco (Municipality of Atenguillo): 12 km NW of Los Volcanes, grassy slopes with Pinus and Quercus , 20°24’00” N, 104°36’23.08”W, 1900 m, 30 October 1973, D. E. Breedlove 35838 (holotype CAS).

Plant perennial, herbaceous, up to 88 cm tall. Stems branched from the base, ascending or the base horizontal and suddenly curved up, green or purple, striate with yellow bands, glabrous with tiny sparse, black, circular dots (smaller than glands of the leaflets), glabrate or sparse-pilose in the middle vein adaxially, the trichomes 0.8–1.4 mm long; stipules 0.9–1.3 mm long, lanceolate to triangular-lanceolate, reddish, with a series of minute reddish, cylindrical ca. 0.1 mm glands at base of the adaxial side; intra-petiolular glands 2, circular, impressed; post-petiolular glands 0–2. Leaves imparipinnate, 1.0– 2.9 cm long, petiole 0.8–4.5 mm long, channeled in adaxial side, glabrous in upper leaves or ciliate-pilose in basal leaves with few, straight, erect to sub-adpressed, fine, white, spiraled twisted, denser in the abaxial side, especially in the midvein, 0.6–1.0 mm long, sparse trichomes; leaflets 4–9 pairs, terminal leaflet petiolulated, 3.6–7.0 mm long, 1.0– 2.3 mm wide, lanceolate-obovate to oblong-obovate, flat or loosely folded, glabrate or sparse-ciliate adaxially, bicolored, lighter abaxially, with sparse, tiny circular glands abaxially. Inflorescences terminal, 2.2–4.7 cm long, the spikes oblong-cylindrical, dense, 0.8–1.2 cm diameter, rachis evident or hidden by flowers, densely pilose, trichomes straight to slightly reflexed, white, 0.3–0.5 mm long. Peduncles elongate, erect, 10.5–22.5 cm long, lateral and terminal, and continuous with the main stem-axis, glabrate, brown to purple, striate. Bracts soon deciduous, 3.0– 3.9 mm long, ovate, acuminate, cuneate at base, abruptly narrow at apex, dark in the distal half, white in the proximal half, densely to sparsely ciliate abaxially, glabrous internally, membranous, with few circular, honey colored, circular oil glands. Flowers 6.5–8.0 mm long, sessile. Sepals united, calyx campanulate, 4–5 x 2–2.4 mm, the tube 2.0– 2.5 mm long, its orifice symmetric or slightly oblique, pilose, the trichomes spread, denser in the upper half and between teeth or edges of the teeth, ribs evident, green in the upper half including the teeth, white or yellow in the bottom half, intercostal spaces with 1–13 irregular, spread circular, honey colored or almost transparent, tiny circular, rarely cylindrical glands; the teeth 1.2–3.0 mm long, triangular-aristate, equal or unequal, and the dorsal one longest, 2.5–3.0 mm long. Petals blue, turning purple when dry, perched well below middle; the banner 6.5–7.8 x 3.1–3.8 mm, deltate, obtuse or slightly cordate in the base, the claw 4.1–4.8 mm long, the blade 2.5–3 mm long, dyed white in the center of the blade and sprinkled with tiny circular glands, or the glands absent; the wings 6–6.3 x 1.5–2 mm, oblong to obliquely oblong, apex rounded, the claw 1.9–2.1 mm long, the blade 4.1–4.2 mm long, with 1 or few apical glands or the glands absent; the keel 8.3–9.0 x 1.7–2.2 mm, its petals valvately coherent, obovate to wide-obovate, straight or slightly incurved, the claw 3.8–4.0 mm long, the blade 4.5–5 mm long. Stamens 10-merous, 6.3–7.5 mm long, the longer filament free for 2–2.5 mm long, the connective gland tipped, the anthers 0.5–0.7 mm long. Ovary elliptic, 1.3–1.5 mm long, sparsely pilose or almost glabrous, the style 5.4–5.9 mm long, linear, glabrous. Pod in lateral view, obovate to oblique-obovate, 2.4–2.6 x 2 mm, the ventral suture almost straight or slightly concave, valves thin, hyaline at base, pilose in the upper half or upper third, glandular; seeds 1.8–2.0 x 1.1–1.3 mm, light brown, semi opaque.

Distribution and habitat:— So far as we know, Dalea jaliscana is known only from the type locality, inhabiting grassy slopes and Pinus and Quercus forest in mountains, at 1800–1900 m elev., in the municipality of Atenguillo, Jalisco.

Etymology:— The species epithet name refers to the state of Mexico where the specimen was collected (Jalisco).

Additional specimens examined (paratypes):— Herbarium collections at ANSM, CAS, CFNL, MEXU, NY, TEX, and US, were reviewed, and to date, there is no record of another collection of this species.

Discussion:— Dalea jaliscana morphologically resembles D. sericea Lag. (Barneby 1976: 541), but can be distinguished from that species by the characters noted in the following key:

1 Perennial herbaceous, 0.25–1.5 m tall; stipules (3–)4–11(–17) mm long; intra-petiolular glands circular; leaflets (2–)4–5(–6) pairs, (4–)5–20(–22) mm long; spikes 2.2–4.7 x (1–)1.3–2.1(–2.9) cm; calyx 4.6–8.7 mm long; petals violet purple, turning blue or bluish-purple when dry; banner 5.7–9 mm long; wings (5.1–) 5.5–8.5 mm long; keel 6.5–10 mm long................................. D. sericea

1 Herbaceous perennial, up to 0.8 m tall; stipules 0.9–1.3 mm long; intra-petiolular glands spiculiform; leaflets 4–9 pairs, 3.6–7 mm long; spikes (1–)1.5–7(–8.5) x 0.8–1.2 cm; calyx 4–5 mm long; petals blue, turning purple when dry; banner 6.5–7.8 mm long; wings 6–6.3 mm long; keel 8.3–9 mm long ..................................................................................................................... D. jaliscana

Dalea sericea occurs in grama grassland and oak-pine forest from 1400–2600 m elevation. It is distributed from Westcentral Mexico to Honduras, and it is sympatric in Jalisco with D. jaliscana .

Figures

FIGURE 1. A. Plant, B. Leaflets (up, adaxial view; down, abaxial view). C. Inflorescence. D. Flower (calyx and petals). E. Bract. F. Calyx. G. Banner (front and lateral view). H. Wing. I. Keel. J. Stamens. K. Ovary and style. L. Fruit.