Nahuatlea hypoleuca (DC.) V.A.Funk, 2017

Funk, Vicki A., Sancho, Gisela & Roque, Nadia, 2017, Nahuatlea: a new genus of compositae (Gochnatieae) from North America, PhytoKeys 91, pp. 105-124 : 118

6. Nahuatlea hypoleuca (DC.) V.A.Funk comb. nov. Figs 3A , 8

Moquinia hypoleuca DC., Prodromus 7(1): 23. 1838.

Gochnatia hypoleuca (DC.) A. Gray, Proceedings of the American Academy of Arts and Sciences 19: 57. 1883.

Type.

Mexico. Neuvo León: Monterrey, January 1828, Berlandier 1391 (Holotype: G 00223915; Isotypes: BM 000947902, GH 00010616, K 000502540, MO 100221306, NY 00230667, P 00703318, P 00703319, P 00703320, US 00119521). [There is a second specimen at NY that is a possible isotype NY 00230666; the specimen from HAL 0112991 may be an isotype but the dates don’t match and the number is listed at "1391 s.n."]

Description.

Shrub or small tree, 2 –5(– 7) m tall; leaves coriaceous, 2-5 × 0.9-1.5 cm, narrowly elliptic, apex obtuse, mucronate, attenuate at base, glabrous adaxially, cinereous-tomentose abaxially; heads sessile or very short pedunculate, in clusters of 5-15 heads at apices and axils of branches, many clusters per plant; involucre narrowly obconic, 4-7 mm tall × ca. 3 mm wide, bracts in ca. 3-5 series, ciliolate-tomentose on the margins but otherwise glabrous; flowers 5-7 per head; corollas white, 10-12 mm long; anther base caudate, tails ca. 1 mm long, fimbrillate; pappus ca. 6.5-7.5 mm long, bristles biseriate, of various lengths and broadening slightly at the tips.

Distribution.

Mexico: Coahuila, Nuevo León, Tamaulipas, Durango, Zacatecas, San Luis Potosi, Queretaro, Hidalgo, and Michoacán. United States: Arizona, Texas.

Remarks.

According to the Texas A&M University website (http://aggie-horticulture.tamu.edu/ornamentals/nativeshrubs/gochnatiahypole.htm) the common names for this shrub in Texas are Chomonque and Ocote. The website goes on to say that it is an "attractive, little-known shrub native to extreme South Texas, Chomonque flowers in the winter and has striking bi-colored leaves, very dark green on top and white and feltish underneath. The white flowers that appear from November to February are weakly fragrant and attract bees and many species of butterflies. It grows on gravel and caliche in South Texas shrub lands, and is extremely drought and heat tolerant. A specimen at the San Antonio Botanical Gardens has proved cold hardy and evergreen, but its cold-hardiness farther north is untested." The website lists the USDA hardiness zone 9.

Figures

Figure 3. Images of four type specimens: A Nahuatlea arborescens (UC holotype) B N. smithii (K lectotype) C N. obtusata (US holotype) D N. hypoleuca (G holotype). [Furnished by the respective herbaria.]

Figure 8. Photos of Nahuatlea hypoleuca from southern Texas. Habit photo from La Puerta, Texas; Fruiting photo from Vaquillas Road, Texas; Flowers from Yturria Brush, Texas. [photos by T. F. Patterson.]