Passiflora tenuiloba Engelm., Boston J. Nat. Hist. 6: 192. 1850.

Porter-Utley, Kristen, 2014, A revision of Passiflora L. subgenus Decaloba (DC.) Rchb. supersection Cieca (Medik.) J. M. MacDougal & Feuillet (Passifloraceae), PhytoKeys 43, pp. 1-224: 84-88

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Passiflora tenuiloba Engelm., Boston J. Nat. Hist. 6: 192. 1850.


6. Passiflora tenuiloba Engelm., Boston J. Nat. Hist. 6: 192. 1850.   Figs 9, 34 -35

Passiflora bigelovii   Small, Bull. N. York Bot. Gard. 1: 283. 1899. Type: United States of America. Texas: "Camp Green", C. C. Parry [Mexican Boundary Survey] 393c (lectotype, designated here: NY! [NY00110395]; isolectotype: GH! [00065785])


United States of America. Texas: "Western Texas, On the Liano", 1869, F. Lindheimer s.n. (holotype: MO! [MO-312539]).


Slender, low-climbing or scrambling, perennial vine 1 m long or more, densely pubescent with unicellular curved trichomes on petiole, and adaxial leaf surface, 0.21-0.38 mm long, 0.02 mm wide, also minutely antrorsely appressed-puberulent throughout with unicellular, curved trichomes, 0.01-0.29 mm long, 0.02-0.07 mm wide. Flowering stems 0.5-1.4 mm in diameter, terete, base somewhat woody and cork-covered. Stipules, 1.9-3.6 mm long, 0.2-0.5 mm wide, narrowly ovate, acute to attenuate, longitudinally striate-nerved; petioles 0.2-1.1 cm long, commonly bearing in the distal half, (0.36-)0.52-0.81 of the distance from the base toward the apex of the petiole, 2, elliptic, opposite, sessile, cup-shaped nectaries with raised rims, 0.8-2.2 mm wide (on the widest axis), 0.2-1.3 mm high. Laminas 0.3-3.7 cm long, 3.0-14.8 cm wide, coriaceous, occasionally variegated as juveniles, 3- to 5-lobed 0.37-0.90 of the distance to the leaf base at the deepest sinus, lateral lobes 0.3-7.0 cm long, 0.1-0.6 cm wide, linear to narrowly ovate, acute to attenuate, often the primary lateral lobes with 1 to 4 smaller lobes, central lobes 0.3-3.7 cm long, 0.1-3.0 cm wide, ovate to oblong, acute to obtuse, often with 2 to 3 smaller lobes toward apex, angle between the lateral lobes 145-343°, ratio of lateral to central lobe lengths 0.58-23.33, margins entire, hyaline, primary veins 3 to 5, diverging and branching at base, laminar nectaries absent or with one submarginal nectary associated with the minor veins of the abaxial surface, 0.6-0.9 mm in diameter, circular to widely elliptic, sessile; tendril 0.1-0.5 mm wide, present at flowering node. Flowers borne in leaf axils. Pedicels 1.3-8.5 mm long, 0.4-0.6 mm wide, paired in the leaf axils; bract(s) absent or rarely with one narrowly ovate, attenuate, bract present on the distal tip of the pedicel, ca. 0.8 mm long, 0.3 mm wide; spur(s) absent. Flowers 12.8-20.6 mm in diameter with stipe 1.1-4.1 mm long, 0.6-0.8 mm wide; hypanthium 4.3-5.9 mm in diameter; sepals 3.9-8.1 mm long, 1.7-4.3 mm wide, ovate-triangular, acute to rounded, abaxially and adaxially greenish yellow; coronal filaments in 2 series, the outer 35-47, 2.7-4.9 mm long, 0.2-0.5 mm wide, linear, tapering to a point or slightly capitellate, reflexed above middle and the tips often slightly incurved, greenish yellow toward the base and yellow toward the tip or reddish purple (5RP 3/4) at the base and yellow toward the tip, ratio of outer coronal row to sepal length 0.44-0.90, the inner 35-50, 1.6-3.1 mm long, 0.1-0.3 mm wide, linear, capitate, greenish yellow with yellow tips or reddish purple with yellow tips, erect, ratio of inner coronal row to outer coronal row length 0.46-0.68; operculum 0.9-1.3 mm long, plicate, greenish yellow with yellow margin or reddish purple with yellow margin, the margin with narrow minutely fimbrillate teeth; nectary 0.1-1.0 mm high, 0.4-0.7 mm wide, slightly sulcate; limen recurved, 0.1-0.7 mm high, 0.2-1.1 mm wide, greenish yellow with a white margin or reddish purple with a white margin, limen floor 1.1-2.9 mm in diameter, greenish yellow or greenish yellow with reddish purple spots and streaks; androgynophore 2.9-4.2 mm long, 0.8-1.2 mm wide, greenish yellow or greenish yellow with reddish purple spots and streaks; free portions of the staminal filaments 1.9-3.6 mm long, 0.3-0.7 mm wide, linear, greenish yellow; anthers 1.7-2.9 mm long, 0.5-1.9 mm wide; styles 2.5-4.0 mm long including stigmas, 0.2-0.5 mm wide, greenish yellow; stigmas 0.6-1.0 mm in diameter; ovary 1.0-2.6 mm long, 0.9-2.4 mm wide, globose to slightly obovoid, greenish yellow. Berry 7.1-14.6 mm long, 7.3-15.3 mm in diameter, ovoid to obovoid, very dark purple. Seeds 12-25, 4.1-4.8 mm long, 1.9-2.5 mm wide, 1.3-1.5 mm thick, obovate in outline, acute at both ends, reticulate-foveate with each face marked with ca. 17-25 foveae.


Flowering and fruiting March to December.


Northern Mexico and southern Texas in the United States. Arid and semiarid thorn scrub (e.g., Mesquite-Black brush, Opuntia   - Prosopis   scrub, Tamaulipan thorn scrub) and grasslands; climbing on shrubs or scrambling on limestone outcrops and hills, or in open grassy areas on very limited to moderately developed soils; ca. 150-1500 m.


Passiflora tenuiloba   is very distinctive in the form of the leaves. It possesses leaves that are shallowly to deeply 3- to 5- lobed, often with lateral lobes that are up to 8.0 cm long and between 0.2 and 2.1 cm wide. The lateral lobes frequently possess 2-3 lobes at their apices. The central lobe is short (<1.0 cm) or longer (to 3.7 cm), sometimes with three lobes at its apex. The petiolar glands are positioned on the distal half of the petiole, often at the petiole apex or even on the base of the leaf. Passiflora tenuiloba   also has very distinctive seeds with reticulate centers and grooved edges.

Passiflora tenuiloba   occurs in southwest Texas and northern Mexico along with Passiflora pallida   . The small flowers of these two species are somewhat similar, but they can be easily separated by vegetative characters. The most obvious difference is the shape of the lamina, with Passiflora tenuiloba   possessing leaves that are transversely elliptic and Passiflora pallida   possessing leaves that are ovate to elliptic in general outline. In addition, the flowers of Passiflora tenuiloba   have a wider hypanthium than those of Passiflora pallida   and have more and commonly longer filaments in their coronal rows. The seeds of Passiflora tenuiloba   are 4.1-5.8 mm long, whereas those of Passiflora pallida   do not exceed a length of 3.5 mm.

Passiflora tenuiloba   has been included in three other studies of passionflowers. Benson et al. (1975) found that Agraulis vanillae   (Gulf Fritillary) is an herbivore of this species. Klucking (1992) found that the leaf venation pattern of this species is similar to Passiflora sexocellata   and Passiflora eglandulosa   and was classified as actinodromous and pinnate secondary venation with irregular to regular intercostal venation consisting of lineate and transverse veins. According to Klucking, the leaves of Passiflora tenuiloba   are more like those of Passiflora eglandulosa   , because they have acute lateral lobes, an angle between the lateral veins that is between 120 and 140°, and leaf bases that are cordate.

Engelmann, in his description of Passiflora tenuiloba   , states that the type specimen was collected in October "on the Liano" (likely meaning "on the llano") by Lindheimer and that only a single specimen was collected ( Goldman 2004). The specimen, which is clearly labeled as being collected "on the Liano" and possesses a Latin description of Passiflora tenuiloba   from Engelmann, is held at the Missouri Botanical Garden (MO). There is another specimen collected by Lindheimer at MO, but it is not type material. The form described as Passiflora bigelovii   possesses central leaf lobes that are longer and nearly equal in length to the lateral lobes. Small (1899) cites three specimens in his description of Passiflora bigelovii   , but did not designate a holotype. Killip (1938) listed Parry 393c as the type of Passiflora bigelovii   , but did not officially designate it as a lectotype or discuss the other specimens (syntypes) cited by Small. I have selected Parry 393c as the lectotype for Passiflora bigelovii   , as the specimen is the most complete with leaves, flowers, and fruits.

Selected specimens examined.

UNITED STATES. Texas: Bandera Co.: N side of F.M. 470 ca. 300 ft. W of road-summit in Seco Pass, 9.3 mi. E of F.M. 187, Seco Pass Quadrangle, Carr 9090 (TEX). Bexar Co.: on Austin Chalk plain at mouth of Government Canyon, E side of current main entrance road, W side of abandoned entrance road, 0.6 mi. N of gate at 90° curve on Galm Rd., ca 5.0 mi. (by air) WSW of jct. SR 16 and Loop 1604, 29°32'35"N, 98°44'54"W, 980-990 ft., Carr 14560b (TEX). Blanco Co.: Tharp 203 (TEX). Brewster Co.: 3 mi. from mouth of Heath Canyon, Correll 31586 (LL). Brown Co.: Dallas, Reverchon s.n., 12 August 1877 (NY). Burnet Co.: Marble Falls, Carsuer & Studhalter 4338 (TEX). Crockett Co.: 22 mi. W of Ozona on U.S. 290, Flyr 5 (TEX). Dimmit Co.: Chaparral Wildlife Management Area, Gilbert s.n., 10 May 1979 (TEX). Duval Co.: Texas hwy. 359, 6.5 mi. E of Bruni, Texas, Vergara et al. 8570 (TEX). Edwards Co.: along the edge of Rt. 674, 6.9 mi S of the intersection with Rt. 377, and around 10 mi SW of Rocksprings, 29°56"N, 100°20"W, Goldman 1782 (UT). El Paso Co.: W Texas, on the road to El Paso del Norte, Schott s.n. (NY). Hays Co.: San Marcos and vicinity, Stanfield s.n., June 1897 (NY); NW from Kyle, Tharp 1538 (TEX, US). Hidalgo Co.: E side of Sullivan City, Correll & Johnston 18048 (TEX). Jim Hogg Co.: 17.6 mi. SW of Hebbronville along Farm Rd., 3073 to Miranda City, Turner & Turner 15119 (TEX). Jim Wells Co.: along S.R. 624, ca. 5 mi. N of Orange Grove, Brown 4884 (NA). Kerr Co.: Turtle Creek, Bray 164 (TEX, US). Kinney Co.: 15 mi. E of Brackettville on hwy. #90, Butterwick et al. 316 (TEX). La Salle Co.: near Cotulla, Laredo to San Antonio, Small & Wherry 11947 (NY). Live Oak Co.: 7.2 mi. N of Live Oak-Jum Wells County line, Rt. 281, Escobar et al. 602 (TEX). Mason Co.: Johnson City, Mason, Whitehouse 203 (TEX). Maverick Co.: S side of Eagle Pass, Correll & Wasshausen 27734 (TEX). McMullen Co.: 4.8 mi. S of Loma Alto, Cory 17227 (GH). Medina Co.: Hondo, 750 ft., Pillsbury s.n., 12 April 1903 (PH). Pecos Co.: Madera Mts., 28 mi. S of Ft. Stockton on road to Marathon, Correll & Schweinfurth 25413 (TEX). San Patricio Co.: s. side of Park Rd., 0.2mi E. of the entrance to a Boyscout camp, Camp Karankawa, just n. of Lake Corpus Christi State Park, and around 3mi SW of Mathis, 28°03"N, 97°52"W, Goldman 1770 (BH); s. side of Park Rd., 0.2mi E. of the entrance to a Boyscout camp, Camp Karankawa, just n. of Lake Corpus Christi State Park, and around 3mi SW of Mathis, 28°03"N, 97°52"W, Goldman 1771 (BH). Sterling Co.: Sterling Co. hills, Tharp 3615 (US). Sutton Co.: uncommon along X 290, 14.2 mi. E of Sonora, Mears & Mears 1492 (TEX). Terrell Co.: along Rio Grande between Reagan Canyon & Sanderson Canyon, 2000 ft., Warnock 15857 (TEX). Travis Co.: Austin, above Barton Creek, 1 mi. S of Loop 360, 600 ft., Larke 1 (TEX, NY). Uvalde Co.: Concan, Palmer 10192 (CAS, US). Val Verde Co.: 4 miles west of Langtry, Johnston 6485 (LL); near entrance to Seminole Canyon State Park, along hwy. 90, 29°42'N, 101°19'W, Turner & Zhao 16025 (TEX). Webb Co.: State Hwy. 359, 7 mi. E of Laredo, Ramos et al. 200 (DUKE, TEX). Wilson Co.: Sutherland Spring, Palmer s.n., August 1879 (GH). Zapata Co.: 13.9 mi. N of San Ygnacio along US Hwy. 83, W side of hwy. along either side of the barbed wire fence line, locality best marked as between 2.1 and 2.3 mi. S of county line marker (Webb/Zapata counties), Turner 80-68M (TEX).

MEXICO. Coahuila: 22 mi. N of Nueva Rosita, near K163, 1500 ft., Bates et al. 1479 (CAS, TEX, NY); cañon de La Barrica (S-draining), gently SW-sloping upper-bajada-type area in mouth of canyon, 27°00'02"N, 102°23'50"W, 1490 m, Wendt & Lott 1232 (TEX). Nuevo León: Mpio. Higueras; W side of Mex 85, 10 km N of Cienega de Flores, ca. 1.6 km S of El Ranchito, near S end of major curves in hwy., 26°01'30"N, 100° 07'15"W, 480-540 m, Bridges & Woodruff 13121 (TEX). Tamaulipas: 48 mi. from Reynosa on the San Fernando Road, 27 mi. from Matamoros-San Fernando hwy. turnoff, Graham & Johnston 4376 (GH).

CULTIVATED MATERIAL. United States: North Carolina, Durham, Duke University, cultivated from material collected 17 June 1978 at Pedernales State Park, Texas, MacDougal 227 (FLAS).