YUCCA VERDIENSIS


Yucca verdiensis, sp. nov.


Planta acaulis vel fortasse brevicaulis; comis foliorum solitariis vel paucis; laminis foliorum gracilibus pler-umque 0.4-0.7 rariter ad 1.3 cm. latis, margine plus minusve filiferis; inflorescentia 2.1-2.7 m. longa, parte florifera paniculata, basin versus ramulis laxis elongatis donata, apice conspicue racemosa; scapo e coma foliorum eyidenter project»; floribus parvis 4-4.5 cm. longis segmentis fragilibus; pistillo parvo 2-2.5 cm. longo; ovario gracili; stylo gracili albo vel dilute viridi 0.7-1 cm. longo fere oblongo-cylindrico; capsulis plerumque symmetricis ca. 4.5 cm. longis ca. 2.5 cm. crassis fragilibus extus levis vel rariter rugulosis.


Plants acaulescent to caulescent, forming a single head or small, congested clumps with several heads; stem at most short, hidden beneath reflexed leaves. Head of leaves open or crowded, asymmetrical, rather untidy. Base of mature leaf small, where thickened near union with blade lenticular, elsewhere flat, broad-triangular, median length 2-2.5 cm., breadth at insertion 3.2-4 cm., at union with blade 0.7-1.3 cm., margins papery, brittle, epidermis finely striate, cream. Blade of mature leaf 25-32-45 cm. in length, uniformly slender, very sightly narrowed above union with base, then gradually and very slightly broadened to well above middle, thence tapered to acuminate apex, greatest width 0.4-0.7-rarely 1.3 cm., commonly straight, on outer surface slightly keeled or rounded for entire length, on inner surface slightly convex near union with base, elsewhere flat to near apex where occasionally slightly concave, where thickened for 10-13 cm. above base stiff, elsewhere very flexible, smooth, finely striate on both surfaces, pale blue- or yellow-green; leaf-margins at first white, after fibres have separated same color as blade; fibres fine, those separating first near top of blade straight, subsequent ones tightly or loosely curled and soon massed below, eventually margins nearly smooth; spine acicular, about 5 mm. long. Inflorescence 2.1-2.7 m. in length overall (scape longer than flowering portion); inflorescence proper panicled, raised high above leaves, 1-1.3 m. in length, rarely branched throughout, usually with a few long, wide-spreading basal branchlets and long, con­spicuous racemose tip about 1/2-2/3 of entire length of flowering portion, little crowded; branchlets commonly fragile, twiggy, 3-10 in number, 10-20-35 cm. in length, spreading-ascending to horizontal; pedicels very slender; flowers produced singly, in pairs or rarely in threes, small, 4-4.5 cm. in length, with base (united portion of perianth) short, 3-5 mm. in length, nearly tubular or spreading-cup-shaped, with very thin, fragile, elliptical to nearly ovate or obovate, acuminate perianth-segments, much the same length in both ranks; those of inner row broad, ca. 2 cm. in breadth, often extremely concave; those of outer row narrow, about 1.3 cm. in breadth, flattish; filaments usually reaching to near middle of style, 2-2.5 cm. in length, each free at base from those adjacent, their lower portion extremely slender, their clavate tip about 5 mm. in length, erect or spreading-ascending, well-differentiated from lower portion, swollen, pubescent; pistil 2-2.5 cm. in length; ovary 1.5-2 cm. in length, very slender, 0.4-0.5 cm. in diameter, oblong-cylindric to slightly obovoid, with rounded shoulders and no appreciable neck; style white or palest green, 0.7-1 cm. in length, very slender, 2-3 mm. in diameter, oblong-cylindric, terminating at apex in 3 nearly erect, rather large stigmas of "tufted" appearance; fruit averaging 4.5 cm. in length, ca. 2.5 cm. in breadth, at times constricted near base and spreading above but usually symmetrical, short-mucronate, capsular wall very fragile and light, epidermis smooth or slightly roughened, drying a pale tan or gray; at delu'scence splitting to base on primary fissures, on secondary fissures for about 1/2-2/3 of length of capsule, 3 carpels round-backed below, above flattened or a little indented in center and marked with a faint, very slender median rib, sides of locules (along primary fissures) often twisted; old floral base nearly tubular, about 0.7 cm. in length; pedicels about 1.7 cm. in length, terete; seed small to medium sized, glossy.


Range. Mainly confined to central and eastcentral Arizona (Yavapai and Gila Counties), from the regions about the Verde and East Verde Rivers southeastward to the Gila River. For range map see p. 86.


ARIZONA. Y a v a p a i C o . : Between Clarkdale and Cottonwood, May 7, 1933, McKelvey 2752 (type), 2750, 2751 (AA). — Common on mesas between Camp Verde and Clemenceau, May 22, 1935, A. Nelson and R. A. Nelson 2058 (M 1128275). — ? Camp Lincoln [= Camp Verde], August 6, 1866, E. Palmer (M 148655). — Fort Verde, August 27, 1887, E. A. Mearns 348 (N); same locality, 1888, E. A. Mearns 348 (N). — Acaulescent, leaves gray-green, soft and flexible, scape 2.2 m. high, 4 miles south of Camp Verde, alt. 990 m., June 24, 1939, R. H. Peebles 14413, with 2 photos. (AA). — Verde Valley, June 18, 1920, W. W. Jones 35 (G). — ? Sandy draws, Prescott, April 28, 1925, A. Nelson 10242 (UC 467277). C o c o n i n o C o . : Near Walnut Canyon, alt. 1700 m., August 1, 1901, J. B. Leiberg 5797 (W 410622). G i l a C o . :? Pine Valley, June, 1890, M. E. Jones (PO 190457). — ? Sycamore Creek, between Payson and Pine, February 20, 1929, McKelvey 738 (photo. [4X5 series] 24-4) (AA). —Three miles north­west of Pine, alt. 1830 m., July, 1928, C. B. Wolf 2458 (S 190363) (G) (CA 173884). —On road to Packard, May 20, 1929, A. Eastwood 17354 (G) (N) (CA 167921). — ? Roosevelt Dam, April 19, 1937, A. Eastwood (CA 109967); same locality and date, A. Eastwood 6206 (CA 109968). — Tonto Basin, July 19, 1892, J. W. Tourney 443 (AA). — Strawberry Valley, July 21, 1892, J. W. Tourney 443 (W 212039) (S 52673). — Salt River, (Highway 60), hillsides, May 26, 1935, J. Whitehead 1294 (W). — ? Pleasant Valley, January 9, 1874, J. B. Girard 4 (M 148429). — ? San Carlos Indian Reservation, San Carlos to Cazador [? = Cazadero] Spring, June 24, 1904, F. V. Cowlle 1911 (W 500589). N a v a j o C o . : Four miles south of Holbrook, flowering stalk 2.5 m. high, with 6 branches below the main spike, June 17, 1901, L. F. Ward (W 410328) (N). — Forestdale, Apache Reservation, 66 miles south of Holbrook, July 4, 1901, W. Hough 90 (W 562896, 890145).


Yucca verdiensis was seen by the writer in May, 1932, when circling from Prescott to Jerome, Clarkdale, Camp Verde, and, via Cherry Creek and Dewey, back to Prescott; two divides were crossed on the last part of the trip, one, perhaps both, in the Mingus Mts. In the Verde River valley, at about 1050 m. elevation, between Clarkdale and Cottonwood and on to Camp Verde the species was plentiful, between Cherry Creek and Dewey was seen again but stopped on the ascent of the last divide leading to Prescott; all this region lies in northeastern Yavapai Co., Arizona.


Although plants were mainly acaulescent a few had made stems which were 1-1.3 m. in height and mostly hidden under reflexed-spreading dead leaves; they suggested Y. data, — the inflorescence raised high above the leaves on a long scape and overall attaining 1.8-2.5 m.; the flowering portion (shorter than the scape for the most part) varied in form, at times slender, almost racemose, again branched broadly below and narrowly above when it approximated still others, the prevailing sort, with a few long, wide-spreading, basal branchlets and long, conspicuous, racemose tip; the leaves, while varying in length and in breadth averaged narrow. Flowers were not open in early May but buds were far enough advanced to prove that the style was white or palest green; their descrip­tion has been based mainly on dried material. In herbarium collections flowers are small, the pistil also, with a slender ovary and slender, and, in relation to the ovary, rather long style; it has been impossible to study the stigmas satisfactorily but in general they seem to give a rather "bunchy" or "tufted" look to the top of the style; the fila­ments are slender below, the clavate tip slightly swollen and turned at a considerable angle to the lower portion, and at anthesis they reach commonly to about the middle of the style, in one instance, however, surpassing the stigmas. Old fruit in May was still in good condition; although showing less constriction and distortion, the light weight of the capsules, their thin, fragile wall and smooth, pale tan epidermis, bore a close resem­blance to what is found in Y. angustissima; also, in both species, there occurs along the primary fissures, a curious twisting of the exposed sides of the locules at dehiscence, apparently to be explained by the fact that these, held tightly together at base, are frus­trated in their attempt to expand fully, or to the same plane as the backs of the carpels, and consequently at the point of strain become somewhat warped or twisted; however, since this tendency is rarely apparent in fragile-walled capsules of other species some structural peculiarity may be responsible.


McKelvey 2752, May 7, 1932, from between Clarkdale and Cottonwood, Yavapai Co., Arizona, is named as type; McKelvey 2750, 2751 are of the same date and from the same region; the type consists of inflorescence buds, foliage and old fruit.


Dr. Edward Palmer* in 1866 seems to have made the first collection of Y. verdiensis (if one may judge by slender foliage only) at Camp Lincoln, another name for Camp Verde according to Arizona Place Names (468, 1935); since 1866 many others have found it and much of the material is satisfactory. The recent Peebles 14413, from 4 miles south of Camp Verde, is accompanied by excellent photographs of the fruiting plant and, in 1939, from Mr. J. Pinckney Hester the writer received a photograph taken "near Fort Apache," which shows a group in full flower. Of Peebles 14413 Kearney and Peebles (Flowering Plants and Ferns of Arizona, 198, 1942) wrote under Y. elata: "In Arizona, mature plants usually have well-developed stems and often are very tall, but a stemless form has been found at Camp Verde, Yavapai County. ..."


Herbarium collections are all from central and eastcentral Arizona, extending from eastern Yavapai Co. across Gila Co., with one number from southern Coconino Co., and two from southern Navajo Co. The northern collections, including the type, are mainly from regions adjacent to the Verde and East Verde Rivers, the southern from between Tonto Creek and the Gila River (between these flows the Salt River east of Roosevelt Reservoir). Whether Y. verdiensis occurs directly about this Reservoir is uncertain; Miss Eastwood's collections therefrom, of extremely slender leaves, appear to be this species; fruit on one sheet (CA 109967) is closer to that of Y. verdiensis than to that of Y. elata which grows in the region; a large cluster of leaves (CA 169460) from "Near Roose­velt" is not cited but this, again, is probably the same (see next paragraph). The range of Y. verdiensis covers a country of mountains and mountain valleys. It seems possible that the plant may have an even more extensive range and spread north*** and northwest and east and southeast; it is to be expected in Arizona in the San Francisco Mts. and in the ranges lying between the Coconino Plateau and Colorado River; and in New Mexico, in the mountainous areas of Catron and Socorro Counties (the racemose inflorescence with basal branchlets associated with Y. intermedia var. ramosa, found in Torrance Co., New Mexico, differs in its shorter scape which brings the flowering portion close to or among the leaves; flowers and foliage also distinguish these plants). In line with the belief that this Yucca may extend northeastward in Arizona are field-book notes of April 26, 1934, made between Hackberry and Peach Springs, in northeastern Mohave Co.; with these is a rough sketch of an inflorescence, very suggestive of that of F. verdiensis; the notes read: "... in same group measured a branched inflorescence ... 5 ft. 10 in. overall; 2 ft. 5 in. length of racemose tip; 12 branchlets about 8-14 in. in length which are confined to the top of scape ... no fruit . . . leaves long, finely filiferous, the young white-margined; heads of leaves large; plants with 2 ft. stem ..." Since (apart from the old stalk) only foliage was present, no collection was made. This would seem to be a region where a number of species come into proximity; Y. kanabensis (McKelvey 2779, 2546, 4084), Y. angustissima (McKelvey 2256, 2257, 2545, 2764) and perhaps Y. standleyi because (see p. 107) there are suggestions of intermediates between that species and Y. angustis­sima. In so far as the extension of Y. verdiensis into westcentral New Mexico is concerned the writer is in some doubt as to the species prevalent over the Plains of St. Augustine; she passed through this region after dark and what plants could be seen suggested Y. elata which is found farther east, to the west of and about Socorro; but they need more careful examination.


The fruit and foliage of a Yucca growing to the northeast of Roosevelt Reservoir, in the Sierra Ancha, Gila Co., bore a striking resemblance to what is found in F. verdiensis. This plant was at first thought to be an unusual form of Y. elata for, although smaller, its habit was also arborescent; but the foliage was unusually narrow and extremely iiliferous and its entire appearance neater than in Y. elata, — the dead reflexed leaves closely, tidily appressed to the stem (in Y. elata they are loosely reflexed or spreading and the effect is shaggy); the photograph 44-7 (4x5 series) (pl. XXXV) shows this plant which seems to grow at higher elevations in these mountains than does Y. elata which was seldom seen except in their lower reaches. McKelvey 2148 (leaves, fruit) constitutes all the material*** and some doubt must exist as to the determination until more collections, flowers in particular, have been secured; the fruit, however, bears a close resemblance to that of Y. verd­iensis, in form and manner of dehiscence and in color also. It seems possible that this plant may represent the mature form of our species, the plants of the Verde River valley and thereabouts (which sometimes produce short stems) constituting younger colonies - for the Sierra Ancha might form part of, as they certainly adjoin, the range of Y. verdiensis. Variations in all aspects of a plant are found on range outskirts and, as has already been noted, F. verdiensis in certain regions was unstable in form of inflorescence proper. McKelvey 2148 is not cited.


There is considerable similarity between Y. verdiensis and Y. angustissima: the cap­sules of both are rather small, with thin wall, smooth epidermis and, at or after dehiscence, the sides of the locules show a tendency to twist which is not common in other species; the foliage of both averages slender. Yucca verdiensis seems to range mainly southeast of Y. angustissima and one wonders whether it might perhaps represent a panicled, mountain variety of the racemose desert plant. However, its small flowers with extremely small and slender pistil and its very long scape, which raises the panicled flowering portion high above the leaves, bear no resemblance to those of Y. angustissima.


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*) One sheet of the Palmer collection (M 148654), not cited, includes one large packet (a capsule and seed) and three small packets of seed, perhaps taken from the large; the date and erasures on the large packet suggest that there was some doubt as to the date of collection; Parry forwarded the seed in June, 1870, or four years after Palmer collected it; the seed is larger than that of other collections of Y. verdiensis, such as Peebles 14413, and it may have come from a F. data collection. Much Yucca material attributed to Palmer appears unreliable in labelling and origin. Trelease noted on this specimen: "Y. radiosa? Seeds too large for angustissima.."

**) A plant with panicled inflorescence was seen to the east of Flagstaff; field-book notes state that "McKelvey 4495 suggests Y. elata;" the fruit of the specimen cannot be found unfortunately. It might well be Y. verdiensis or, less likely, Y. utahensis extending southeastward; it seems very improbable that Y. elata occurs about Flagstaff.

***) The photograph 44-7 is associated in the writer's field-book with her collection 827 of March 7, 1929, but the foliage of this collection is not that of the plant of the picture but Y. elata; some error must have taken place; the picture should be associated with 2148, collected on May 10, 1931, when the plant was revisited.


© Yuccas of the Southwestern United States 2, 1947