130 NORTH AMERICAN FLORA [VoLuME 21 
a short or elongate tube, or the stamen rarely only 1; anthers 2-celled. Ovary 
1-ovuled, the ovule pendulous. Radicle ascending. 
Flowers glomerate, the leaves subtending the glomerules usually indurate at 
the base and forming an involucre in age. ’ 12. TipEsTROMIA. 
Flowers capitate or spicate, the heads or spikes naked or subtended by leaves, 
but, in the latter case, the leaves not indurate at the base. 
Stigma capitate, sometimes bilobate. 
Stamen-tube 5-lobed, without pseudostaminodia. 
Lobes of the stamen-tube entire. 
Flowers terete. 13. GossyPIANTHUS. 
Flowers compressed. 15, ACHYRANTHES. 
Lobes of the stamen-tube 3-lobed, dentate, or laciniate. 14, PFAFFIA. 
Stamen-tube 4-10-lobed, the antheriferous lobes entire, alternating 
with pseudostaminodia. 15. ACHYRANTHES. 
Stigma 2- or 3-lobed, the lobes subulate to filiform. 
Stamen 1; sepals 4. 16, WoEHLERIA. 
Stamens 2-5; sepals 5. 
Lobes of the stamen-tube broad, 3-lobed, dentate or laciniate; 
pseudostaminodia none. 17. GOMPBRENA. 
Lobes of the stamen-tube entire, often with intermediate pseudo- 
staminodia. 
Leaves, at least most of them, alternate. 18. Dicraurus. 
Leaves all opposite. 
Flowers not compressed, in small spikes, these loosely panicu- 
late. 19, IRESINE. 
Flowers strongly compressed, in dense, axillary or terminal, 
head-like spikes. 
Stamens 2; perianth sessile. 20. LITHOPHILA. 
Stamens 5; perianth stipitate. 21. PHILOXERUS. 
12. TIDESTROMIA Standley, Jour. Wash. Acad. Sci.6: 70. 1916. 
Cladothrix Nutt.; (Mog. in DC. Prodr. 132: 359, as synonym. 1849) S. Wats. Bot. Calif. 2: 43. 
1880. Not Cladothrix Cobn, 1875. 
Annual or perennial, erect or prostrate herbs, sometimes suffruticose at the base, branched, 
pubescent with branched hairs. Leaves opposite, petiolate, the blades broad, entire. Flowers 
minute, perfect, glomerate in the axils of the leaves, bracteate and bibracteolate, the bracts 
and bractlets hyaline, pubescent; perianth 5-parted, the segments equal, 1-nerved, mem- 
branaceous. Stamens 5, hypogynous; filaments connate into a short cup, with or without 
intervening lobes or staminodia; anthers 2-celled. Ovary globose; style short; stigma capitate, 
simple or 2-lobed; ovule 1, suspended from the apex of a slender funicle. Utricle slightly 
compressed, glabrous. 
Type species, Achyranthes lanuginosa Nutt. 
Annual, usually prostrate; staminodia very short or none. 1. T. lanuginosa. 
Perennials, erect or ascending. 
Staminodia very short and broad, sometimes emarginate. 2. T. suffruticosa. 
Staminodia acute, nearly half as long as the filaments. 3. T. oblongifolia. 
1. Tidestromia lanuginosa (Nutt.) Standley, Jour. Wash. Acad. 
Sci. 6: 70. 1916. 
Achyranthes lanuginosa Nutt. Trans. Am. Phil. Soc. II. 5: 166. 1820. 
Alternanthera lanuginosa Mog. in DC. Prodr. 137: 359. 1849. 
Cladothrix lanuginosa Nutt.; (Moq. in DC. Prodr. 132: 360, as synonym. 1849) S. Wats. Bot. 
Calif. 2: 43. 1880. 
Prostrate or procumbent annual, much branched, the branches slender or stout, 1-5 dm. 
long, densely and finely stellate-pubescent or sometimes glabrate in age; petioles slender or 
stout, equaling or shorter than the blades; leaf-blades orbicular to oval or ovate-orbicular, 
0.5-3 em. long and about as broad, rounded or obtuse at the apex and base, densely stellate- 
pubescent on both surfaces, or, in age, often glabrate on the lower or both surfaces, the veins 
often prominent beneath; glomerules few-flowered, the subtending leaves sometimes indurate 
at the base in age; perianth 1-3 mm. long, 3 times as long as the bracts, the segments narrowly 
oblong to ovate-oblong, obtuse or acutish, yellowish, densely stellate-pubescent or glabrate; 
staminodia minute or wanting; seed 0.5 mm. long. 
‘Tyee Locanity: ‘Sand beaches of Great Salt River’’ [Oklahoma?]. 
DistTRIBUTION: Dry plains and fields, western Kansas to southeastern Utah, south to western 
Texas, Sinaloa, and Zacatecas. 
ILLUSTRATIONS: Britt. & Brown, Ill. Fl. f. 1411; ed. 2. f. 1673. 
