novelties in hedeoma (labiatae)

NOVELTIES IN HEDEOMA (LABIATAE)

ROBERT S. IRVING

Irving, R. S. (University of Montana, Missoula). Novelties in Hedeoma (Labiatae). Brittonia 22: 338-345. 1970.--Hedeoma pilosum and H. micro- phyllum are described as new. The former, an endemic of western Texas, is closely related to H. pusi~lum and H. apiculatum; the latter is intermediate between H. costatum and H. nanum. H. oblongi]olium var. mexicanum and H. drummondii var. crenulatum are presented as two new varieties, both of which may have originated as hybrids. Hedeoma crenulatum is proposed as a new name to replace H. montanum (Brade) Epling & J{ttiva. Three new combina- tions are made in the genus Hesperozygis, and new status is accorded to two species.

Hedeoma is a widespread genus of herbaceous annuals and perennials distributed primarily in the southwestern United States and northern Mexico. In the most recent treatment (Irving, 1968) it comprises 42 taxa, many of which are newly described. Because of the necessity of validating the new data for the "Manual of the Vascular Plants of Texas" (Correll & Johnston, 1970), it seems appropriate to submit the following report in advance of the final monograph.

Hedeoma mierophyllum Irving, sp. nov. Figs. 1-4.

Herbae perennes, 10-17 cm altae; surculi multi, internodiis minus quam 5 mm longis; folia densa, conferta, ovate, 3-5 mm late, 4-6.5 mm longa supra glabra, subtus puberulenta, marginibus serrulatis et ciliatis, nervatione prominula; cymulae 1-3- florae; calyx 5.5-6.5 mm longus, paullo saccatus; corolla caerulea circa 8.5 mm longa, intus glabra; nuculae circa 1 mm longae, circa 0.5 mm latae.

Tuf ted perennials 10-17 cm high, arising from a slender taproot or trailing root- stock. Shoots numerous, decumbent or ascending with branching more or less restricted to the base, puberulent or hirtellous with hairs retrorsely curving. Leaves numerous and crowded, ovate, 3-5 mm wide, 4-6.5 mm long, margins obscurely serrate, the base rounded or weakly cuneate, petiolate, the petiole ca. 1 mm long, apex acute, glabrous above, minutely puberulent below and on the margins; nerves conspicuously elevated, the secondaries of 2 or 3 subopposite, curved and unbranched pairs diverging from the midrib at ca. 30 ~ Cymules 1-3-flowered (occasionally up to 5-flowered), well spaced or crowded along the stems; pr imary peduncles inconspicuous, less than 1 mm long; primary pedicels ca. 3 mm long, hirtellous; bracteoles shorter than the pedicels. Calyx 5.5-6.5 mm long, the tube 4-4.5 mm long, the abaxial surface saccate below but not markedly so for ca. one-half of the tube's length, the distended region ca. 1.2 mm wide dorsiventrally, moderately hirsute with spreading or slightly recurving hairs, the upper teeth connate for ca. one-third of their length forming an upper lip ca. 1.5 mm long, the lobes reflexed and spreading, narrowly triangular, ca. 0.4 mm wide at the base, ca. 1 mm long, hirsute or hirtellous-ciliate, the lower teeth recurred, subulate, ca. 0.5 mm wide at the base, 2 mm long, hirsute or hirtellous-ciliate; annulus included, ca. 0.5 mm wide and seated at the juncture of the upper and lower teeth. Corolla blue, ca. 8.5 mm long, glabrate within, the tube ca. 7 mm long, slender, slightly dilated upwardly, ca. 0.5 mm wide at the summit, the upper lip ligulate, slightly concave, straight or curling slightly upwardly, emarginate, ca. 1 mm wide, ca. 1.5 mm long, the lower lip ca. 3.5 mm wide, ca. 3 mm long. Nutlets ca. 1 mm long, ca. 0.5 mm wide.

BRITTOI~X.~ 22: 338--345. October-December, 1970.

338

1970] IRVING: HEDEOMA 339

FIG. I. Hedeoma microphyllum Irving. General habit )< ~ . FIG. 2. Calyx >( 7.5. FIG. 3. Corolla )< 7.5. FIG. 4. Leaf undersurface X 7.5.

TYPE: M E X I C O : SAN LuIS POTOSi: 10 km W of Guadalc~zar, Aug 1966, Irving 693. (HOLOTYPE: T E X ! ISOTYPE: M O N T U . )

Dis t r ibut ion: Canyons north of Ciudad San Luis Potosi, San Luis Potosi, Mexico. Flowering Ju ly to September.

340 BRITTONIA [voL. 22

Representative specimens:

MEXICO: SA~ Lvls POTOSi: Charcas, Lundell 5402 (LA, MICH, NY) ; west of Guadalc~izar, Irving 707 (MONTU, TEX).

Hedeoma microphyllum is abundant where encountered. At the type locality it was a prominent member of the herbaceous flora and occupied most of the open eroded areas on a north-facing hillside.

The phenetic affinities of Hedeoma microphyllum are difficult to assess. Its costate venation and serrate margins are features peculiar to the H. costatum complex. How- ever, the diminutive leaves, the saccate calyx tube, and the overall growth habit suggest a strong relationship to H. nahum. As both H. nanum and H. costatum are sympatric over a large geographic area which encompasses the current distribution of H. microphyllum, a hybrid origin for the latter may be considered. However, none of the characters of H. microphyllum are intermediate in themselves but are rather an admixture of those found in H. costatum and H. nahum. This resorting of characters would indicate a stabilized hybrid derived through a series of recombinants. This too is supported by the absence of interplant variation in a series of generations grown in the greenhouse.

t t e d e o m a p i losum Irving, sp. nov.

Herbae perennes caespitosae, 4 cm altae; folia ovata integra, sessilia, 5 mm longa, 2.5-3 nun lata, margine pilosa alibi glabra, apicem versus angustata, acuta; flores singulares, axillares; calyx infundibuliformis pilosus, 7.5 mm longus, dentibus superis deltatis, 1.5 mm longis, ad medium usque connatis, dentibus infernis lanceolatis, circa 2.5 mm longis, omnibus piloso-ciliatis; annulus densus, in parte centrali tubi situs; corolla fructusque ignoti.

A small perennial caespitose herb ca. 4 cm high, probably forming mats. Stems herbaceous, extremely short, unbranched above, profusely branched below, pubescent with short spreading hairs. Leaf pairs crowded, the internodes ca. 1.5 mm long. Leaves coriaceous and sharply ascending, appressed to the stems, ovate, entire, sessile, tapered to a narrowly obtuse or acutish apex, 5 mm long, 2.5-3 mm wide, margins pilose-ciliate, the upper and lower surface glabrous, with 1 or 2 slightly raised subopposite secondary veins diverging from the midrib at acute angles, straight and craspedrome. Flowers solitary in the uppermost leaf axils; primary peduncles short; pedicels 1-2 mm long, canescent with short retrorsely directed hairs; bracteoles short, oblong, ciliate. Calyx 7.5 mm long, somewhat coriaceous, the tube tubular- funnelform, not at all gibbous below, dilated upwardly, ca. 5 mm long, pilose, the hairs long and spreading, the upper teeth connate for ca. one-half of their length, forming a broad upper lip, ca. 2.5 mm long, the lobes triangular, ca. 1.2 mm long, ca. 0.5 mm wide at the base, slightly laterally spreading and reflexed, pilose-ciliate, the lower teeth narrowly triangular-lanceolate, ascending, ca. 2.5 mm long, pilose- ciliate; annulus dense, included, ca. 1.i mm wide, seated deep within the tube ca. 2 mm below the juncture of the upper and lower lips. Corolla and nutlets not observed.

TYPE: TEXAS: Brewster County: near top of Baldy Peak, Glass Mountains, 13 July 1940, Warnack 352. (HOLOTYPE: GHi)

Distribution: Open exposed limestone of "Old Blue" (Baldy) Mountain, Texas. Hedeoma pilosum together with H. ciliolatum, t t . pusiUum, and H. apiculatum

form a very distinct and perhaps relict line within the genus. All of the taxa are narrow endemics of the mountains of northern Mexico and western Texas. Initially, it was difficult to find morphological cohesion in this group of species. The discovery

1970] IRVING: HEDEOMA 341

FIc. 5. Hedeoma drummondi i Benth. var. crenulatum Irving. General habit X �89 FIG. 6. Calyx X 7.5. FIG. 7. Corolla X 7.5. Fro. 8. Leaf X 7.5.

342 BRITTONIA [VOL. 22

of H. pilosum, however, provided the necessary morphological intermediacy to unify the group. Hedeoma pilosum is intermediate between H. pusillum and H. apiculatum. Its pulvinate habit and costate leaves place it clearly near H. pusillum from which it can be separated by the details of the calyx, especially the pilose pubescence. The sunken annulus, the glabrous inner faces of the calyx teeth, and the overall con- figuration of the calyx however are features which indicate its relationship to H. apiculatum.

Due to the incompleteness of the specimen, we still lack both chromosomal and morphological data. Thus, the phenetic and possibly phyletic position of H. pilosum is tentatively presented. Unfortunately a revisit to the type locality during the summer of 1968 did not reveal any trace of H. pilosum, and it may well be extinct.

HEDEOMA DRUMMONDII Benth. var. e r e n u l a t u m Irving, var. nov. Figs. 5-8.

Herbae perennes 15-30, cm altae; folia ovata, 5-7.5 mm longa, margine crenulata, utrinque uniformiter pubescentia; calyx 5-5.5 mm longus; corolla ca. 11 mm longa.

Tall, robust perennials, 15-30 cm high, somewhat woody at the base but not suffruticose. Shoots numerous from the base, ascending and branching freely along the axis, densely puberulent, nearly cinereous with tightly retrorsely curling hairs. Leaves dark green, usually deciduous in the lower one-half of the shoots at maturity, cernuous or spreading, membranous, ovate, 5-7.5 mm long, 3.5-6 mm wide, margins crenulate, the base rounded, shortly petiolate, apex obtuse, both surfaces and margins evenly densely antrorsely puberulent. Cymules crowded along the upper one-fourth to one-half of the stems with 1-5 flowers per cymule; primary peduncles ca. 1 mm long; primary pedicels ca. 3 mm long, retrorsely puberulent. Calyx 5-5.5 mm long, the tube 3-5 mm long, finely pubescent or hirtellous, the tapered neck partially closing the orifice and then only well after anthesis, the upper calyx teeth subulate, ca. 0.1 mm wide at the base, 1-1.2 mm long, erect convergent with the lower to close the orifice, the lower teeth ca. 0.4 mm wide at the base, 2-2.5 mm long; annulus dense, ca. 0.8 mm wide, seated ca. 0.8 mm below the juncture of the upper and lower teeth. Corolla blue, ca. 11 mm long; the tube ca. 3 mm wide (dorsiventrally) at the summit, the upper lip ca. 1.5 mm long, the lower lip 3-4 mm wide, ca. 3 mm long. Nutlets ca. 0.5 mm wide, ca. 1 mm long.

TYPE: MEXICO: SAN LuIs PoTosI: 7.8 mi W of Guadalc~zar, 10 Aug 1965, Irving 632. (HOLOTYPE: TEX! ISOTYPE: MONTU!)

Distribution: Limestone hills and river bottoms in the state of San Luis Potosi, Mexico. Flowering in August.

H. drummondii var. crenulatum intergrades with var. drummondii, but can be separated from the latter by its elongated, ovate crenulate leaves.

HEDEOMA OBLONGIFOLIUM (A. Gray) Heller var. m ex i ean u m , Irving, var. nov. Fig. 9-11.

Herbae perennes 28-40 cm altae; folia anguste elliptica vel linearia 9-13 mm longa 1.5-4 mm lata, 3-plo longiora quam latiora; calyx 5.2-5.8 mm longus; corolla 8-9 mm longa, intres annulata.

Stout perennials 28-40 cm tall. Shoots few, pubescent with tightly retrorsely curling hairs above, puberulent below, branching mostly confined to the lower regions of the stem with the secondary branches long and ascending at close angles. Leaves spreading, narrowly elliptical or linear, at least three times as long as wide, 9-13 mm long, 1.5-4 mm wide, the margins denticulate with the teeth confined to the distal regions of the blade, the base tapered and subsessile, the apex sharply acute, the

1970] IRVING: HEDEOMA 343

FIG. 9. Hedeoma oblongi]olium (A. Gray) Heller var. mexicanum Irving. General habit )< 1/2. Fla. 10. Calyx >( 7.5. Fla. 11. Corolla X 7.5.

surfaces glabrous or glabrate above, glabrate below, nerves elevated, the secondaries consisting of 2 or 3 subopposite, straight, unbranched pairs which depart from the midrib at acute angles. Juvenile foliage distinct from the adult, narrowly elliptical to ovate, entire, and evenly glabrate. Cymules 5-10-flowered, dense and congested,

344 BRITTONIA [VOL. 22

well spaced or crowded along the upper two-thirds of the shoots; primary peduncles inconspicuous; primary pedicels, 4-5 mm long, puberulent; bracteoles lanceolate. Calyx 5.2-5.8 mm long; the tube 3.7-4.2 mm long, gibbous below for ca. one-half of the tube's length, the distended region 1-1.2 mm wide dorsiventrally, the tube hirtellous with short, stiff, spreading hairs, the upper calyx teeth only slightly united to form an upper lip 0.9-1 mm long, the lobes narrowly triangular, subulate, 0.1-0.2 mm wide at the base, 0.8-0.9 mm long, laterally spreading and reflexed, hirtellous-ciliate, the lower teeth subulate, recurved, ca. 0.3 mm wide at the base, 1.2-1.7 mm long, hirsute-ciliate; annulus dense, ca. 0.5 mm wide and seated approxi- mately at the juncture of the upper and lower teeth. Corolla 8.9-9 mm long, lavender, annulate with short hairs; the tube 6.8-7.8 mm long, slightly dilated upward, the upper lip ligulate, emarginate, ca. 1 mm wide, 1.2 mm long, conspicuously shorter than the lower lip, reflexed away from the axis, the lower lip spreading, ca. 3 mm wide, ca. 3 mm long. Nutlets ca. 0.5 mm wide, ca. 1 mm long.

TYPE: M E X I C O : SONORA: Puerto del Cumarito, Sierra de la Cabellera, 5400 ft, 6 Oct 1941, W h i t e 4638. (HOLOTYPE: M I C H ! ISOTrCPES: GH! US!)

Distribution: Common in the oak woodland and chaparral associations in the mountains of northern Sonora and Chihuahua, Mexico. 6000-9000 ft. Flowering August to October.

Representative specimens:

MEXICO: CHIHUAttUA: Sierra an Mecia, Nelson 6486 (GH, K, US); near Colonia Garcia, Townsend & Barber 282 (BM, K, NY, UC, US) ; Colonia Ju~irez, Jones s.n. 12 Sep 1903 (POM), Pennell 19039 (PH, US) ; 10 mi E of Madera, Muller 3491 (GH, MICH, UC). SONORA: between San Pedro and Fronteras, Hartman 924 (GH); Janos, White 955 (MICH); Canyon de Bavispe, White 3245 (MICH); NE of E1 Tigre, White 4269 (F, GH, MICH, NY, US); Rancho de la Nacla, White 3937 (MICH).

H. oblongi]olium var. m e x i c a n u m can be differentiated from the more northern variety, H. oblongi]olium var. eblongi]olium, by its narrowly elliptical glahrate leaves and its annulate corolla.

H e d e o m a e r e n a t u m Irving, nom. nov. (Based on Pseudo cunila mon tana Brade.)

Hedeoma polygalaelolium Benth. var. montanum Dus6n, Arch. Mus. Nac. Rio de Janerio 13: 35. 1903. TYPE: BRAZIL: Sr~RRA Do ITATTAIA, Mar 1894, UIe 199. (HOLOTYPE: R)

Pseudocunila montana Brade, Rodrigudsia 7: 27. 1944. TYPE: BRAZIL: Rio DE JAmEIRO, Serra dos Orgaos, 2200 m, A. C. Brade 11500. (HOLOTYPE: RB!)

Cunila montana Brade ex Epling, Brittonia 7: 140. 1951. TYPE: BRAZIL: Rio CASTELLO: Rio de Janeiro, Serra dos Orgaos, 2100 m, 17 Jan 1945, Segadas Vianna 675. (r~OLO'rYPE: LA !) [In ignorance of the above name as indicated below.]

Hedeoma montanum (Brade ex Epling) Epling & Jittiva, Brittonia 15: 369. 1963. (non Brandegee, 1911) Based on Cunila montana Brade ex Epling.

Hecleoma crenatum is a rare species found in the mountains of Minas GerMs and Rio de Janeiro. I t was first recognized by Dus6n as a variety, m o n t a n u m , of H. polygalae]olium. Brade in 1944, in spite of his knowledge of Dus~n's work, described it as a new species for his newly created monotypic genus, Pseudocunila. He elected not to use the type designated by Dus~n. Later, the affinity of this taxon was reevaluated by Epling, and the species placed in the genus Cunila. Epling, however, unaware of Dus~n's and Brade's publications, and seeing only an annotated herbarium specimen, created still a third type. In 1963, Epling transferred C. mon tana to Hedeoma apparently unaware of H. m o n t a n u m Brandegee. I am, however, in agree- ment with Epling's treatment of this taxon as a species of Hedeema.

The genus Hesperozygis is represented by species in both North and South America. In both its original circumscription (Epling, 1936; Epling & Stewart, 1939) and in

1970] IRVING: HEDEO1V[A 345

subsequent addi t ions (Epling, 1940) the genus housed a bewildering a r ray of inter- specific variat ion. Indeed there were few morphological features which could serve to unify the genus. As a result of careful s tudy of representat ive specimens i t was discovered that in overall habi t and calyx configuration the South American mater ial formed a ra ther coherent unit readily separable from the Nor th American taxa. The latter, with the exception of H. marifolia, are actual ly members of the genus Hedeoma displaying affinit ies to a var ie ty of lines. Thus, the following new combinations are proposed:

H e d e o m a e i l i o l a t u m (Epling & Stewart) Irving, comb. nov.

Hesperozygis ciliolata Epling & Stewart, Repert. Sp. Nov. Beih. 115: 13. 1939.

H e d e o m a p u s i l l u m (Irving) Irving, comb. nov.

Hesperozygis pusilla Irving, Brittonia 19: 245. 1967.

H e d e o m a b e l l u m (Epling) Irving, comb. nov.

Hesperozygis bella Epling, Bull. Torrey Bot. Club 67: 512. 1940.

Hedeoma ciliolatum and H. pusillum are closely allied sympat r ic species of Nuevo Le6n, Mexico, which with H. pilosum and H. apiculatum form a ra ther distinctive unit within Hedeoma.

Hedeoma bellum is somewhat more ambiguous. I t is a very rare species restricted, so far as known, to one population in Jalisco, Mexico. However, in the details of both vegetat ive and floral morphology, especially tha t of the nutlets, it is clearly related to the H. piperitum-jucundum group also of the Sierra Madre Occidental.

Hedeoma reverckonii Gray vat. s e r p y l l i f o l i u m (Small) Irving, s tat . nov.

Hedeoma serpylliyolium Small, Bull. New York Bot. Gard. 1:287. TYPE: TEXAS: Kerr Co.: Kerrville. 25-30 Apr 1894, Hdler 1663. (HOLOTYrL: N.Y.!; ISOTYrES: GH! IA! MICH! MSC! ND! NY! PH! SMU! UC! US!).

Hedeoma costatum Gray var. p u l e h e l l u m (Greene) Irving, s ta t . nov.

Hedeoma pulchellum Greene, Leaflets Bot. Obs. & Crit. 1: 213. 1906. TYPE: NBw MF~XlCO: Sierra Co.: Kingston, 19 May 1905, Metcalfe 1599. (~OLO~ZPE: ND!; IsozYPES: NMC!; PIIOTOTYPE: LA !).

I would l ike to thank Ri ta Panloski for her excellent i l lustrat ions and Marshal l C. Johnston for his help with the La t in diagnoses.

LITERATURE CITED

Correll, D. S. & M. C. Johnston 1970. Manual of the Vascular Plants of Texas. Renner, Texas: Texas Research Foundation. xv + 1881 pp. (Contr. Texas Research Foundatio~n, Bot. Studies vol. 6.)

Epling, C. 1935-1937. Synopsis of the South American Labiatae. I. Repert. Sp. Nov. Beih. 85(1): 1-96. 1935; II. 85(2): 97-192. 1936; III. 85(3): 193-288. 1936; IV. 85(4): 289- 341. 1937. (cf. 85(2) : 132-134. 1936.)

1940. Supplementary notes on American Labiatae. Bull. Torrey Bot. Club 67: 509-534.

& W. S. Stewart 1939. A revision of Hedeoma with a review of allied genera. Repert. Sp. Nov. Beih. 115: 1--49.

Irving, R . S . 1968. The systematics of Hedeoma. Thesis: Ph.D. Univ. Texas, Austin.