Dalea hegewischiana

Title

Dalea hegewischiana

Author(s)

Rupert C. Barneby

Scientific Name

Dalea hegewischiana Steud.

Description

58.  Dalea hegewischiana Steudel

(Plate LXV)

Perennial herbs, weakly suffrutescent at base in age, the slender, stramineous or purplish, verruculose stems humifusely radiating from the root-crown or short caudex, or (in protection of brush) rarely assurgent, (1.5) 2.5-8 (14) dm long, freely branching from base or at least from near the middle, the lateral branches often forming fanshaped sprays, the earliest spikes leaf-opposed but most of them terminal to leafy branchlets, the whole commonly glabrous up to the ciliolate orifice of calyx but some young branchlets, or young leaves, or stipules and bracts, or raceme-axes (or some of these) often thinly pilosulous with widely spreading hairs less than 0.5 mm long, the foliage bicolored, the leaflets green above, pallid or glaucescent and punctate beneath, some axillary innovations appearing low on the stems following or during late anthesis sometimes densely gray-pilosulous; leaf-spurs up to 0.5 mm long; stipules linear- subulate, pallid, brownish, or livid, 1-2.5 mm long, becoming dry and fragile; intra-petiolular glands 1, rarely 2, subulate or conic; post-petiolular glands prominent, conic, orange; leaves subsessile or short-petioled, the main cauline ones 1-3 (4.5) cm long, with narrowly margined, remotely punctate rachis and 6-15, rarely only 4-5 pairs of obovate, oblong-obovate, obovate-cuneate, or oblong-elliptic, emarginate or retuse, flat or loosely folded leaflets 1.5-5 mm long, the leaves of distal branchlets often shorter, with fewer (sometimes as few as 4) pairs of smaller leaflets; peduncles 0.5-3.5 (6) cm long; racemes mostly (10) 15-50-flowered, rather loose (when pressed the flowers falling into 2-3 ranks and not concealing the glabrous to thinly pilosulous axis), without petals 6-7 mm diam, becoming 1-5.5 cm long; bracts deciduous, narrowly elliptic or oblanceolate, 1.5-3 mm long, pallid or castaneous in lower livid- greenish and gland-verruculose distally, dorsally glabrous, ± pilosulous at least above middle within; pedicels 0.1-0.5 (0.7) mm long, charged at apex with a pair of glandular grains; calyx 2.6-3.4 mm long, the pleated, blunt-angled, lustrously hyaline, glabrous tube 2.2-2.7 mm long, 1.7-2.2 mm diam, the castaneous or hyaline ribs filiform, the intervals charged with 1 large (2 medium) and 1 superposed smaller, orange blister-glands, the green, broadly ovate or deltate teeth 0.3-0.8 mm long, gland-apicu- late and often gland-spurred, pubescent within, the dorsal one slightly longer and narrower than the rest; petals bicolored, the banner opening whitish with green eye, rubescent, the epistemonous ones ruby- or claret-purple (when dry roseate), often paler along outer edges, perched 1.2-2,5 mm above hypanthium, the banner often and keel always gland-tipped, the banner sometimes glandular in the eye; banner 4.2-4.8 mm long, the claw (1.6) 1.9-2.5 mm, the ovate-cordate blade 2.3-3 mm long, 2.6-3.2 mm wide, recessed at base into a shallow cornet; wings 2.1-4 mm long, the claw 0.3-1 mm, the lance-ovate or -oblong blade 2.3-3.2 mm long, 1.2-1.6 mm wide; keel (detached, either a trifle shorter or longer than banner) 4.1-5.1 mm long, the claws 1.1-1.6 mm, the broadly ovate-elliptic blades 2.9-3.8 mm long, 1.6-2.3 mm wide; androecium 10-, rarely 8-9-merous, 4.5-5.8 mm long, the longer filaments free for 1.2-2 mm, the connective gland-tipped, the anthers 0.4-0.55 mm long; pod 1.8-2.2 mm long, triangular in profile, the very short style-base at comer, the prow slenderly carinate, the valves hyaline in lower 2/3, green and charged with a few small golden glands distally, either pilosulous along the prow or glabrous; 2n = 14 (Mosquin ). — Collections: 20 (viii).

Gravelly and sandy bluffs and hilltops, usually in open, actively eroding sites, on chalky pumice, limestone, and volcanic bedrock, more rarely on brushy and grassy hillsides in thorn-forest, 1470-2400 m (4900-8000 ft), locally abundant in scattered stations in n.-centr. Oaxaca and s. Puebla, there crossing the low divide e. to the edge of Tehuacan desert, thence n.-w. over the plateau to the s. third of Hidalgo and immediately adjoining Queretaro and Mexico; formerly on Cerro de Chapultepec in Cd. Mexico, but not recently collected in Distrito Federal. — Flowering June to January, sometimes again in spring. — Representative: Queretaro. Tequisquiapan: Waterfall 13,929 (OKLA). Hidalgo. Tula: Pringle 6937 (F, MEXU, MICH, NY, US). Tequixquiac, Rose & Painter 6623 (NY, US). Pachuca: Pringle 6936 (M, W, Z). Mexico (Edo): Teotihuacan: Kenoyer A85 (F). Mexico (D. F.): W. Schumann 186 (BM, M, W). Puebla. Tepeaca: Amable distrib. Arsene 3579 (L, NY). Santiago Miahuatlan: Ripley & Barneby 14,720 (NY). Tehuacan: Holway in 1903 (GH, NY). Izucar de Matamoros: Ripley & Barneby 13,691 (CAS, NY, US). Petlalcingo: Ripley & Barneby 13,677 (NY). Oaxaca. Huajuapan de Leon: Ripley & Barneby 13,644 (CAS, K, MEXU, MICH, NY, US). Nochixtlan: Ripley & Barneby 14,587 (NY, US). Teposcolula: Ripley & Barneby 13,666a (CAS, MEXU, NY, US). Etla: Ripley & Barneby 14,626, 14,658 (DAO, NY). Oaxaca de Juarez: M. Carlson 1435 (F).

Dalea hegewischiana (Hegewisch, Hanoverian traveller in Mexico) Steud., Nom. Bot., ed 2, 1: 480. 1840, a legitimate substitute for D. laxiflora (loose-flowered) Schlechtd., Linnaea 12: 293. 1838.— "In terris Mexicanis (Hegewisch, hb. Lehm. et Bueck)." — No typus found, but the protologue agress in most details; cf. discussion infra.— Non D. laxiflora Pursh, 1814. — Dalea rosea (pink) D. Dietr., Syn. Pl. 4: 1017. 1847, a later, superfluous substitute for the same. Parosela hegewischiana (Steud.) Rydb., N Amer. Fl. 24: 57. 1919.

Dalea schaffneri (Johann Wilhelm Schaffner, -1882) Hemsl., Diag. Pl. Nov. 7 1878. — "Mexico: prope Chapultepec, Schaffner." — Holotypus, collected in June 1854, K! — Parosela schaffneri (Hemsl.) Rose, Contrib. U. S. Nat. Herb. 12: 273. 1909.

Parosela lasiostoma (with hairy-mouthed calyx) Rose, Contrib. U. S. Nat. Herb. 8: 305. 1905. — "Collected by G. C. Pringle on chalky bluffs near Tula, Hidalgo, 1902 (no. 8723, type) and at Cieneguilla, Oaxaca, November 1, 1894 (no. 5657)..." — Holotypus, US! isotypi, ARIZ, GH, L, M, MEXU, NY, W, Z!

Parosela campylostachya (with bent spikes, i. e. incurved to vertical) Rose, Contrib. U. S. Nat. Herb. 12: 272. 1909. — "Collected by C. G. Pringle near Cieneguilla [ = between Las Sedas and Tomelin, mun. Etla], November 1, 1894 (no. 5657)..." — Holotypus, US! isotypi, ENCB, MEXU!

A diffuse or humifuse perennial dalea with neat glaucescent foliage, easily recognized by the small, short-toothed, externally glabrous and lustrous calyces elevated on short pedicels and charged in the depressed intercostal membranes with 1-3 large, golden or orange blister-glands. The petals are bicolored, the banner opening whitish except for a small greenish eye-spot, finally rubescent, the epistemonous ones vivid ruby-red or wine- colored, sometimes appearing pallid in pressed specimens. The plants may be truly glabrous, except for silvery-pilosulous hairs inside the bracts and calyx-teeth, but the young branchlets are often puberulent and the young leaves may be pilosulous on one or both sides and ciliolate. In some specimens the summer growth that has borne flowers is hairless, but gives rise close to the ground to densely pubescent, gray-pilosulous innovations. Rydberg (1919, pp. 56, 57) maintained a pubescent Parosela schaffneri and a glabrous P. hegewischiana, but this is manifestly incorrect, for the actual type-collection of D. schaffneri is partly of the glabrous type, a mixture encountered on Chapultepec also by W. Schumann (cited supra). Over most of its range the leaflets of primary cauline leaves are seldom less than eight pairs, at least in some leaves, but on the high, cool and dry plateau in southern Hidalgo the species is represented by a depauperate form in which all leaves are reduced to about 4-6 pairs. I would think this variation worthy of some taxonomic notice except for the fact that Pringle collected at Tula some plants with no more than six but others (isotypi of P. lasiostoma) with 6-9 (10) pairs, the latter not significantly different from the common Puebla-Oaxaca form, although it was so interpreted by Rose. The original D. lasiostoma, which included elements of the plateau and the Oaxacan type, was proposed in ignorance of the earlier D. schaffneri and D. laxiflora, and was correctly reduced to synonymy by Rydberg. The description of P. campylostachya, calling for 21-45 leaflets, is simply erroneous.

Although no typus of D. laxiflora Schlechtd. has been seen, I am content to follow Rydberg in this matter. The protologue is detailed and describes the species very well except for a few points, probably of no importance. Schlechtendahl has the stems shrubby and erect, but the growth-habit of daleas in difficult to interpret from dried specimens and the discrepancy can be ignored. The spikes were said to reach a length of 3 inches, greatly in excess of anything collected since, and this does raise a difficulty. On the other hand, the description of the characteristic and unusual calyx, taken in conjunction with detailed measurements of the petals and the 8-10 pairs of small leaflets, suggest no other known species.

Rydberg (1919, p. 57) referred here with interrogation the still doubtful synonym Trichopodium glandulosum Presl. It is suspected, however, that this was based on a species of Marina.