410 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



1. Forsellesia spinescens (A. Gray) Greene, Erythea 1: 206. 1893. 



Glossopetalon spinescem A. Gray, PI. Wright. 2: 29. pi. 12. 1853. 



Type locality: "In a mountain ravine near Frontera," Texas. The type came 

 from within a few miles of the southern boundary of New Mexico. It may even have 

 come from the south end of the Organ Mountains. 



Range: "Washington and California to Colorado and western Texas. 



\ \.\v Mexico: Upper Corner Monument; San Andreas Mountains; Llano Estacado; 

 Organ Mountains. Dry hills, in the Upper Sonoran Zone. 



A rare shrub of dry rocky slopes, mostly on limestone soil. 



2. PACHISTIMA Raf. 



Prostrate evergreen shrub with glabrous opposite short-petioled serrulate leaves; 

 flowers solitary or in few-flowered axillary cymes; calyx 4-lobed, with a short tube; 

 petals 4; ovary 2-celled; capsule small, 1 or 2-seeded. 



1. Pachistima myrsinites (Pursh) Raf. Fl. Tellur. 42. 1838. 



Ilex ? myrsinites Pursh, Fl. Amer. Sept. 119. 1814. 



Type locality: "On the Rocky Mountains and near the Pacific Ocean." 



Range: British Columbia and California to New Mexico. 



New Mexico: Zuni Mountains; Carrizo Mountains; Sandia Mountains; Bear Moun- 

 tains; Cloudcroft; Mogollon Road; Tunitcha Mountains; Chama; Lookout Mines; 

 Santa Fe Canyon. Woods, in the Transition and Canadian zones. 



3. MORTONIA A. Gray. 



A low shrub; leaves elliptic, thick, entire, acute, contracted into a very short petiole, 

 crowded, 1 cm. long or less; stems yellowish like the leaves; flowers in short terminal 

 bracteate racemes; whole plant densely scurfy. 



1. Mortonia scabrella A. Gray, PL Wright. 2: 28. 1853. 



Type locality: "Mountain-sides, near the San Pedro, Sonora," and "Mountains 

 near El Paso." 



Range: Western Texas and southern Arizona, south into Mexico. 



New Mexico: Upper Corner Monument (Mearns 64, 247). Dry hills, in the Lower 

 Sonoran Zone. 



85. ACEEACEAE. Maple Family. 



Small or large trees with smooth exfoliating bark; leaves opposite, simple and pal- 

 mately lobed or pinnately compound; flowers polygamous or dioecious, in axillary 

 racemes or corymbs; sepals 4 or 5; petals as many or mostly wanting; stamens as many 

 an the sepals, rarely 8, inserted on a disk, or the disk wanting; pistil of 2 or more united 

 carpels, becoming 2 laterally winged samaras. 



KEY TO THE GENERA. 



Leaves simple or palmately 3-foliolate; young branches red- 

 dish or gray; flowers polygamous 1. Acer (p. 410). 



Leaves pinnately 3 or 5-foliolate; young branches green; flow- 

 era dioecious 2. Negundo (p. 411). 



1. ACER L. Maple. 



Trees with reddish, brownish, or grayish twigs, rather smooth bark, and palmately 

 5-lobed or 3-foliolate leaves; flowers polygamous, preceding the leaves, inconspicuous, 

 on slender pendent pedicels; petals sometimes present: fruit as described for the 

 family. 



