LYTHRACEAE. 239 



cylindric, 7.5-30 cm. long, with slender oblong tubercles, 2.5-3 cm. 

 long; areoles with a dense row of very short, dark, more or less per- 

 sistent bristles at upper edge; spines yellow, the sheathed ones 4-5, 

 1-3 cm. long, the lowest longest and usually reflexed; and 4 ap- 

 pressed short radial ones mostly on lower edge of pulvinus; flowers 

 greenish yellow, tinged with red without, 2.5-4 cm. broad; fruit 

 ovate, less than 2.5 cm. long, at length dry; seed flat, 6 mm. broad, 

 with a channeled commissure and conspicuous persistent funiculus. 

 Frequent on the interior plains east of Monrovia; also in the 

 Santa Clara Valley, Ventura County. 



4. O. prolifera Engelm. Stems 1-3 m. high, much branched 

 and often forming thickets, with reticulated wood; joints cylindric, 

 dark green, 7.5-15 cm. long, 3.5-5 cm. thick; areoles tomentose and 

 the older with fine straw-colored bristles; spines 8-10, variable, with 

 large loose yellowish or rusty sheaths, 2.5-3.5 cm. long, 1 subcentral, 

 the others stellate-spreading; flowers dark red, 3.5 cm. broad; fruit 

 clavate to subglobose, strongly tuberculate like the joints, often 

 proliferous; seeds large, 6 mm. broad with broad commissure. 



Common about San Diego. Known in our region only at San 

 Pedro, where it is growing on bluffs near the bay. 



Family 71. LYTHRACEAE. Loosestrife Family. 

 Herbs or shrubs, often trees In tropical regions, mostly 

 with opposite leaves and solitary or clustered perfect 

 flowers. Stipules usually none. Calyx persistent, free 

 from the ovary, but generally enclosing It, the limb 

 toothed and often with accessory teeth in the sinuses. 

 Petals as many as primary calyx-teeth or none. Sta- 

 mens various, inserted on the calyx; anthers versatile, 

 longitudinally dehiscent. Ovary 2-6-celled, or some- 

 times 1-celled; style 1; stigma capitate, 2-lobed; ovules 

 many, rarely few, anatropous. Capsule 1-several-celled, 

 variously dehiscent or sometimes indehiscent. Endo- 

 sperm none; cotyledons flat, often auricled at base. 



Calyx-tube campanulate or hemispheric. 1. Ammannia. 



Calyx-tube cylindric. 2. Lythrum. 



1. AMMANNIA L. 



Annual glabrous or glabrate herbs, mostly with 4- 

 angled stems, opposite sessile narrow leaves, and small 

 axillary solitary or clustered flowers. Calyx campanu- 

 late, globose or ovoid, 4-angled, 4-toothed, often with 

 small accessory teeth in the sinuses. Petals 4, deciduous. 



