Dalea cylindriceps
Rupert C. Barneby
32. Dalea cylindriceps Barneby
(Plate LI)
Perennial from an orange taproot but not of long duration and often flowering the first season, (2) 3-6 (8) dm tall, glabrous to the spikes, the (1) 3-several stems stout, simple and monocephalous or corymbosely few-branched from near middle, in the lower half or third leafy and spurred at most nodes, the pallid or stramineous branches prominently striate-ribbed and distally microtuberculate, the thick-textured foliage bicolored, the leaflets green (when dried often verdigris) above, pallid-glaucescent and sparsely punctate beneath; leaf-spurs 0.5-1.2 mm long; stipules narrowly subulate or linear-lanceolate, 1-2.5 cm long, livid-castaneous and subglandular, becoming dry and fragile; intrapetiolular glands 2, minute; post-petiolular glands prominent, obtuse; leaves short-petiolate, the primary cauline ones 3-7 cm long, with 3-4 pairs of oblanceolate or oblong-elliptic, mostly acute or acuminate, sometimes obtuse and mu- cronulate, flat or loosely folded leaflets up to (1.2) 1.5-2.5 cm long, the terminal one stalked, longer than last pair, the spur-leaves similar but smaller; peduncles (0.3) 0.6-2 dm long; spikes very dense, conelike, when pressed 9-12 mm diam and presenting on each side 6-8 ranks of closely contiguous calyces, the pilose axis becoming (1.5) 2.5-16 cm long; bracts deciduous only with the disjointing fruiting calyx, 4-6.5 mm long, subdimorphic, the lowest lanceolate to narrowly ovate-acuminate, glabrous dorsally, the interfloral ones narrowly lance-acuminate or -caudate, strongly incurved, submembranous and folded at the narrowed base, distally shallow-concave, herbaceous (becoming papery), castaneous or livid, dorsally densely pilose except for the often glabrescent or glabrous tip; calyx 3.4-4.3 mm long, densely pilose externally with straight, ascending hairs up to 1.6-2.4 mm long, the rather broadly campanulate tube 1.9-2.3 mm long, the dorsal sinus a little recessed but the orifice not much oblique, the castaneous ribs little raised, the nearly flat intervals hyaline, charged with 1 (sometimes irregular) row of 2-5 small pale glands, the teeth of subequal length, 1.5-2.2 (2.6) mm long (0.3 mm longer to 0.5 mm shorter than tube), the dorsal one lanceolate, the ventral pair deltate-ovate; petals whitish or pink, glandless, the epistemonous ones shed on expansion; banner 4.7-6.2 mm long, the claw 2.83.8 mm, the deltate- or ovate-cordate, distally hooded, entire or emarginate blade 1.4-2.7 mm long, 1.6-2.1 mm wide; epistemonous petals isomorphic, 2.1-4.7 mm long, narrowly oblong-oblanceolate, 0.3-0.8 mm wide, narrowed downward into and ± twice as long as the short claw; androecium 5.3-7.7 mm long, the column 2.5-3.4 mm, the free filaments 2.2-4.3 mm long, the anthers ± 0.7-0.9 mm long; pod in profile obliquely obovate, 2.5-3 mm long, strongly incurved, the ventral suture shortest, the dorsal suture becoming greatly thickened and castaneous along the prow, the ascending style-base lateral, the valves hyaline in lower 2/3, thence thinly herbaceous, gland-sprinkled, pilosulous; seed castaneous, 1.7-2.1 mm long, nearly as wide.— Collections: 17 (i).
Dunes, sandy prairies, and sand- or gravel-banks along rivers or intermittent streams, 900-1600 m (± 3000- 5300 ft), widely but discontinuously dispersed over the high prairies between s.-w. South Dakota and w. Texas (upper Cheyenne R. in S. Dakota; forks of Platte R. from w. Nebraska upstream just into Wyoming and in Colorado to Denver; Cimarron River in extreme s.-e. Colorado, adjoining Kansas, and Oklahoma panhandle; headwaters of Canadian R. in n.-e. New Mexico and of Concho R. in w. Texas); disjunctly in scattered stations along the Rio Grande in n.-centr. and s. New Mexico; cf. Wemple, 1970, map 11, as P. compaction). — Flowering late May to September. —Representative: South Dakota: Heyward 539 (NY). Nebraska: Steve Stephens 16,154 (NY); Colorado: Eastwood 34 (UC); Tracy 900 (NY); Weber 5169 ( UC). Kansas: Hulbert 3232 (WIS); C. H. Thompson 26 (NY). Oklahoma: Engleman in 1957 (OKLA, UC, WIS). New Mexico: Ripley & Barneby 8347 (NY); Higgins 5726 (NY). Texas: Tharp 5969 (US).
Dalea cylindriceps (of the massive spike) Barneby, nom. nov., a substitute for Petalostemum macrostachyum (large-spiked) Torr., Ann. Lyc. N. Y. 2: 176. 1827. — "About the Forks of the Platte..." — Holotypus, collected by Dr. Edwin James on Maj. Long’s First Expedition, NY (herb. Torr.)! —Non Dalea macrostachya Moric., 1833.
Petalostemon compactus sensu Swezey, Neb. Fl. Pl. (Doane Coll. Nat. Hist. Soc. 1:) 6. 1891, et auct. plur. recentior.; Wemple, Iowa State Jour. Sci. 45 (1): 68. 1970.— Non Dalea compacta Spreng., 1826.
The adoption for P. macrostachyum Torr. of the epithet compactum, in use during most of the present century, dates back to Swezey’s transfer of Dalea compacta Spreng. in 1891. The transfer was no doubt suggested by the fact that Torrey & Gray (1840, p. 691) had long before cited D. compacta, which they were unable to interpret with any confidence, as a possible synonym of P. macrostachyum. The type-locality of D. compacta, given in the protologue as Red River, Arkansas, is in all probability the present Choctaw County, Oklahoma, but this was not known to Swezey who presents no evidence of having learned any more about D. compacta than was known to Torrey & Gray. As the dispersal of the species in question became better known, Rydberg (1920, p. 128) provisionally reinterpreted the Rio Roxo of Sprengel (Nuttall’s Red River) as the Canadian, inferentially moving the type-locality from the southeastern corner of Oklahoma to its far western extremity in the Panhandle, where P. macrostachyum is known actually at this day only from the Cimarron, not the nearby Canadian valley. In any case there is no reason whatever to suppose that any botanist could have sent P. macrostachyum to Sprengel from what is now western Oklahoma before the year 1826, and still less to suppose that a plant from that region would have been so mislabelled. Assuming that Dalea compacta is in reality the same as Petalostemum decumbens Nutt., it becomes necessary to restore Petalostemum macrostachyum Torr. The unwelcome new epithet cylindriceps is a nomenclatural necessity following reduction of genus Petalostemum to Dalea.
Nuttall’s itinerary en route to Red River in 1819 is described in detail by Geiser, Field & Lab. 24: 43-60. 1956.
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:
