Marina melilotina Barneby

Authors

Rupert C. Barneby

Authority

Barneby, Rupert C. 1977. Daleae Imagines, an illustrated revision of Errazurizia Philippi, Psorothamnus Rydberg, Marine Liebmann, and Dalea Lucanus emen. Barneby, including all species of Leguminosae tribe Amorpheae Borissova ever referred to Dalea. Mem. New York Bot. Gard. 27: 1-892.

Family

Fabaceae

Scientific Name

Marina melilotina Barneby

Type

Holotypus, NY; isotypi, CAS, K, US.

Description

Species Description - Erect monopodial annuals from an orange-brown taproot, 4-8 (10) dm tall, repeatedly (subdichotomously) branching upward from well below the middle to form an airy panicle of broad, umbrella-shaped outline, glabrous up to the pedicels and calyx, the slender, distally filiform stems greenish-stramineous, lustrous, eglandular or only remotely and minutely impressed-punctate, the many racemes mostly leaf-opposed but also terminal to all the ultimate branchlets, the leaflets yellow-green and lineolate above, paler or subglaucescent and minutely punctate beneath; leaf-spurs less than 1 mm long; stipules subulate to linear-attenuate, entire or fimbriolate at base, 1-4 mm long, becoming dry and fragile; intra- and post-petiolular glands small (0.1 -0.2 mm) but prominent, mammiform; main cauline leaves 2-4 cm long, subsessile or shortly petioled, with eglandular, obscurely margined rachis and 3-7 pairs of oblanceolate, obtuse leaflets mostly 4-9 mm long, the terminal leaflet stalked beyond and usually a little longer than the last pair, the larger leaflets distinctly gland-crenu- late; racemes (disregarding depauperate subterminal ones) slenderly peduncled, the peduncles 1-5 cm long, openly 7-20 (25)-flowered, the flowers and fruits loosely ascending, the axis becoming (1) 2-8 (13) cm long; bracts early deciduous, lance- acuminate or elliptic, boat-shaped, 1-4 mm long, keeled dorsally, minutely ciliolate; pedicels filiform, ascending, loosely strigulose, 1-1.5 mm long, charged near apex with a pair of grainlike glands; calyx 4.3-5 mm long, pectinately ciliolate along the sharply prominent ribs and margins of the flat, herbaceous-tipped teeth with stiff, spreading-incurved hairs up to 0.2-0.35 mm long, the tube 2.1-2.5 mm long, the membranous, recessed intervals between the ribs charged with a chain of 6-8 small, elliptic, honey-colored glands, the lance-ovate teeth slightly unequal, the dorsal one longest, 2.2- 2.5 mm long (as long to slightly longer than tube); petals bicolored, eglandular, the banner-blade white with purple lobes, in age rubescent, the inner ones vivid magenta-purple, perched at ± 1.2-2 mm above hypanthium rim, the keel-blades adherent by narrow overlap; banner 3.7-4 mm long, the claw 2-2.2 mm, the pentagonal blade 1.8-2.3 mm long, 2.8-3 mm wide, distally recurved through 45°; wings ± 4.5 mm long, the claw 0.7-1.1 mm, the broadly obovate, short-auricled blade 3.7-4 mm long, 2.5-2.7 mm wide; keel 6.3-7 mm long, the claws 1.8-2.4 mm, the broadly obovate, short-auricled blades 4.7-5 mm long, 3.2-3.5 mm wide; androecium 10-merous, 7-8 mm long, the longer filaments free for ± 2 mm, the connective gland- tipped, the anthers yellowish, 0.7-0.8 mm long; pod nearly 3 mm long, obliquely obovate in profile, with prominent dorsal crest and prow, the style-base latero-terminal, the valves transparent in lowest 1/4 papery and thinly pilosulous distally, charged above middle with 2 subvertical crescents of blister-glands; seed ± 2 mm long. — Collections: 2 (i).

Distribution and Ecology - Brushy hillsides, river-banks, and roadsides, sometimes forming weedy colonies in disturbed soils, in arid grassland and xeric shrubbery, 810-1530 m (2700-5100 ft), seldom collected but perhaps passed over for superficially similar species such as M. scopa and M. neglecta var. elongata, known only from two stations in the e. arm of Balsas Depression, in s. Puebla and n.-centr. Guerrero. — Flowering October to December.

Latin Diagnosis - Marina melilotina (suggesting melilot in habit) Barneby, sp. nov., M. pueblensi (Brandg.) Barneby affinis, sed statura majori, caulibus ad racemos usque glabris, bracteis ab ala- bastris cito deciduis, et praesertim floribus majusculis, calyce 4.3-5 (nec 3-3.7) mm, vexillo 3.7-4 (nec 1.7-2.4) mm, carinaeque laminis 4.7-5 (nec 1.8-2.4) mm longis, andro- ecioque 10-mero 7-8 mm (nec saepius 9-mero 3-4 mm) longo procul abstans. — Herbae annuae elatae, habitu M. scopam Barneby simulantes, sed foliolis paucijugis, calycis tubo secus costas pectinato-ciliolato, necnon legumine compresso remotae. — Puebla: colonial along grassy roadside and on brushy hills adjoining, 5100 ft., n.-w. of Tehuitzingo, Nov 7, 1964, H. D. Ripley & R. C. Barneby 13,686.

Discussion

(Plate XVIII)

This species and M. pueblensis, which occur in the same region and in similar habitats, are similar also in foliage and in the form of the individual flower and pod. The differences between them are of about the same order as between the monophyllidious M. unifoliolata and M. greenmaniana. The flower of M. pueblensis is tiny and inconspicuous even at full anthesis, and the usually nonandrous androecium is proportionately short. By contrast the flower of M. melilotina is showy, with keel-blades ± 5 (not 2-2.5) mm long and a much longer, decandrous androecium 7-8 (not ± 4) mm long. In general M. melilotina is a taller plant, individuals standing alone and uncrowded forming an inversely pyramidal, broad-headed panicle of racemes reaching 8 dm in height, whereas the most vigorous plants of M. pueblensis tend to be diffusely branched mostly near the base, with main branches ascending from near the ground and relatively simple upward. The bracts of M. melilotina are thrown off from under the forming buds in the manner usual in sect. Marina, in contrast to the persistent glumaceous bracts which are such a striking and unique feature of M. pueblensis. In its relatively few leaflets and its pectinately ciliolate calyx M. melilotina resembles M. neglecta var. neglecta, but differs in being annual and monopodial, and in the open and relatively few-flowered raceme. In the type-locality M. melilotina grew in close association with M. neglecta var. elongata, instantly recognized as different by the glabrous calyx.

Distribution

Puebla Mexico North America| Guerrero Mexico North America|