Dalea nemaphyllidia
Rupert C. Barneby
64. Dalea nemaphyllidia Barneby
(Plate LXVIII)
Herbaceous, perennial, up to ± 1 m tall, the slender, virgately erect stems brownish-stramineous charged with small impressed orange glands but not verruculose, at anthesis leafless at base and beyond the middle where branching into panicle of spikes, wholly glabrous below the inflorescence, the foliage glaucescent, the leaflets livid- punctate beneath; leaf-spurs very short; intrapetiolular glands 0 or minute; post- petiolular glands subimpressed; main cauline leaves ±3-4 cm long, subsessile, with narrowly margined, punctate rachis and 7-10 pairs of narrowly linear, obtuse, involute and so subcylindric but ventrally grooved leaflets 10-13 mm long, the rameal leaves shorter, with fewer leaflets of same type, the uppermost leaves nearly or quite suppressed; peduncles slender, divaricate and incurved, 6-14 cm long; spikes shortly but rather loosely 15-25-flowered, without petals ±10 mm diam, the densely silky- villosulous axis less than 2 cm long; bracts early deciduous, the lowest broadly the upper narrowly lance-acuminate, 2.5-4 mm long, thinly pilosulous and gland-pustulate dorsally, pallid at base, livid distally, glabrous within; calyx sessile or nearly so (the pedicel sometimes up to 0.4 mm long), 4-4.4 mm long, the thinly villosulous tube 2-2.4 mm long, not recessed behind the banner, the ribs slender, livid, the membranous intervals charged with scattered glands, the triangular-subulate, gland-spurred teeth densely silky-ciliolate within and around the orifice, the dorsal tooth slightly longer than the rest, ± 2 mm long; petals opening bicolored, the banner whitish, rubescent in age, the inner petals violet or purple, all eglandular, the inner elevated ± 1.5-2 mm above hypanthium rim, the keel-blades united by their outer edges; banner ± 5 mm long, the claw nearly 2.5 mm, the cordate, hooded blade ±3.5 mm long, nearly as wide, recurved through nearly 90°; wings ± 4.5-4.8 mm long, the claw 1.4-1.8 mm, the elliptic blade 3.5-3.8 mm long, ± 1.6 mm wide; keel 5.3-5.8 mm long, the claws 1.7-2.1 mm, the ovate-elliptic blades 4-4.4 mm long, ± 2.4 mm wide; androecium 10-merous, ± 5.5-6 mm long, the longest filament free for ± 2 mm, the connective gland-tipped, the anthers ± 0.6 mm long; pod triangular-obovate in profile, ± 2.7 mm long, the style-base latero-terminal, the dorsal crest moderately thickened, the ventral suture and prow slender, the valves hyaline below the middle, thence thinly papery, villosulous, and sparsely gland-sprinkled; seed ±1.7 mm long.—Collections: 1 (o).
Pine forest, at ± 1200 m (4000 ft), known only from the type-locality on the headwaters of Rio Ameca in interior Nayarit. — Flowering September to November.
Dalea nemaphyllidia (with threadlike leaflets) Barneby, sp. nov., D. pectinatae Kunth et D. escobilla Barneby verosimiliter affinis sed ab ea imprimis foliolis paucis (7-10 nec 16-45-jugis) 2-3-plo longioribus, ab hac foliolis paucis simul ac angustissime linearibus involutis subcylindricis (nec oblongis planis) manifeste discedens. Herbae submetrales infra spicas glaberrimae, caulibus ad medium densiuscule foliatis in paniculam subcorym- bosam fere nudam abeuntibus; flos fere is D. escobilla nisi calycis tubo extus parce villosu-
lo, dentibus paullo longioribus, vexilloque eglanduloso absimilis. — Nayarit: flanks of mountains, in pine-forest, 1200 m, trail from Yxtlan to Juanacata, Oct 2, 1926, Ynez Mexia 900. — Holotypus, CAS; isotypi, G, GH, NY, UC.
In fundamental characters and in general growth-habit this elegant and strongly characterized dalea resembles D. pectinata, D. polystachya, and their allies, but differs from all in the relatively few (7-10) pairs of very long, narrow leaflets which are so strongly involute as to become almost cylindric in section, although preserving a narrow groove along the ventral face. Only D. pectinata has (sometimes) leaflets at once as narrow and glabrous, but they are then much shorter (at most 4, not 10-13 mm long) and, at least in main cauline leaves, about 16-40 pairs. The inflorescence of D. nemaphyllidia suggests a close relationship to D. escobilla, a second species highly localized in Nayarit and, by coincidence, also first collected by Ynez Mexia, only a few days earlier. This differs most obviously in its many broad, flat leaflets; furthermore the calyx is glabrous externally and more shortly toothed.
I have not identified positively the "Juanacata" of Mexia’s label but suppose it to be the Juanacatlan lying about 60 km SW of Yxtlan del Rio in municipio Mascota, Jalisco. The type-locality is said, however, to be in Nayarit. hence probably on the right bank of Rio Ameca s.-w. of Yxtlan.
References: [Article] 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.Multimedia:
