KNOTWORT FAMILY 111 



8. Abronia alpina Brandg. Alpine Abronia or Sand-verbena. Fig. 1593. 



Abronia alpina Brandg. Bot. Gaz. 27: 456. 1899. 



Plant perennial, the prostrate branches forming mats 1-2 dm. in diameter, viscid-puberulent 

 throughout. Leaves 2-3.5 cm. long, blades rounded-oval, entire; peduncles of the inflorescence 

 shorter than the petioles ; bracts lanceolate-ovate, 2-3 mm. long ; heads 1-5-flowered ; perianth 

 lavender-pink, 10-15 mm. long, limb broad; fruit 3-4 mm. long, narrowed at both ends, ob- 

 tusely or acutely 5-angled, reticulate-veined. 



In sandy meadows, Canadian Zone; in the southern Sierra Nevada, California. Type locality: Monache 

 Meadows, Sierra Nevada, California. June-July. 



9. Abronia pogonantha Heimerl. Mojave Sand-verbena or Abronia. Fig. 1594. 



Abronia pogonantha Heimerl, Bot. Jahrb. 11: 87. 1889. 



Abronia angulata M. E. Jones, Contr. West. Bot. No. 8: 39. 1898. 



Annual branching from the base, branches ascending or decumbent, 1-3 dm. long, viscid- 

 puberulent and clothed with villous hairs. Leaves 1.5-5.5 cm. long, blades 1-3 cm. long, ovate- 

 oblong to oblong, rounded at and equal at the base, villous on the midvein ; petioles densely 

 villous and glandular ; involucral bracts scarious, broadly ovate, acute at the apex, 6-9 mm. long ; 

 perianth glandular, 10-15 mm. long, white or pale pink ; fruit 3-5 mm. long, thin in texture, 

 finely reticulate-veined, orbicular-obcordate with 2, rarely 3, regular wing-like lobes, fruits in 

 the center of the head, occasionally wingless. 



In sandy soil, Lower Sonoran Zone; central Inyo County, California, and the western borders of Nevada 

 south to the lower San Joaquin Valley and east through the Mojave Desert, California. Type locality: Mojave 

 River, California. April-June. 



10. Abronia turbinata Torr. Transmontane Abronia. Fig. 1595. 



Abronia turbinata Torr. ex S. Wats. Bot. King Expl. 285. 1871. 

 Abronia latiuscula Greene, Leaflets Bot. Obs. 2: 105. 1910. 



Much-branched annual with erect, ascending or decumbent branches 2-5 dm. long, viscid- 

 puberulent to glabrate. Leaves yellowish-green, rarely viscid, ovate-orbicular, irregular at the 

 base, 2-5 cm. long, blade 12-25 mm. long ; involucral bracts 4-9 mm. long, narrowly ovate-acute 

 to lanceolate; perianth viscid-puberulent, 15-22 mm. long, tube pinkish, limb white; fruits often 

 beaked, short-villous, 3-7 mm. long, the inner usually simple turbinate, often beaked, the outer 

 deeply divided into wrinkled wing-like lobes or shallowly with broad obtuse lobes. 



In sandy soil, Arid Transition Zone; southeastern Oregon south along the eastern slopes of the Sierra 

 Nevada and central Nevada to the Mount Pinos region, California. May-June. 



Abronia exalata Standley, Contr. U.S. Nat . Herb. 12: 318. 1909. A form characterized by wingless or 

 2-winged fruit in which the wings are sharply incurved. The smaller fruits and flowers are by no means confined 

 to this form. The distribution is the same as that of A. turbinata. 



Family 39. ILLECEBRACEAE. 

 Knotwort Family. 



Small diffusely branched herbs, with mostly opposite entire leaves and scari- 

 ous stipules or stipules none in Scleranthits. Flowers small, greenish or whit- 

 ish, cymose. Calyx herbaceous or coriaceous, persistent, 4— 5-parted into distinct 

 sepals or 4— 5-toothed. Petals none. Stamens usually 4 or 5, varying from 1 to 10, 

 hypogynous or perigynous. Pistil one; ovary superior, 1 -celled; styles 2, more or 

 less united ; ovule one, amphitropous ; basal or pendulous. Fruit an achene or utricle, 

 enclosed in the calyx-tube. Seed solitary; endosperm present, surrounded by the 

 curved embryo. 



Nineteen genera and about 100 species of wide distribution in both the eastern and western hemispheres. 



Stipules present, scarious; ovule erect. 



Sepals united below into a short cylindric tube. 



Styles 2-cleft. 1. Achyr onychia. 



Styles 3-cleft. 2. Scopulophila. 



Sepals distinct or nearly so. 



Sepals similar. 



Stipules conspicuous, silvery-scarious; sepals distinct almost to the base, bristle-tipped. 



3. Paronychia. 



Stipules minute; sepals united below into a short turbinate tube. 4. Herniaria. 



Sepals dissimilar, the outer larger and tipped with stout divergent spines. 5. Cardionema. 



Stipules none; calyx-tube indurate in fruit; ovule pendulous 6. Scleranthus. 



1. ACHYRONYCHIA Torr. & Gray, Proc. Amer. Acad. 7: 330. 1867. 



Low spreading glabrous annuals. Leaves opposite, those in each pair unequal in size, 

 spatulate. Stipules scarious, distinct. Flowers small, borne in numerous dense axillary 



