590 COMPOSITAE (COMPOSITE FAMILY) 



Involucre campanulate ; bracts herbaceous, imbricated in several series, the 

 inner long-acuminate, the outer successively shorter and acute. Receptacle 

 flat or convex, foveolate or alveolate. Achenes linear or somewhat turbinate, 

 8-10-costate or -striate, truncate at summit, the basal callosity acute and not 

 expanded; areola lateral. Pappus bright white, soft and fragile, double, 

 namely, of a single short external bristle, and 15-20 short truncate or emar- 

 ginate scales terminating in a long gracefully recurving soft-plumose capillary 

 bristle or awn. Microseris. 



1. Ptilocalais nutans (Geyer) Greene, Bull. Cal. Acad. 2: 54. 1886. Slen- 

 der, 1-3 dm. high; fusiform roots either fascicled or solitary: leaves entire 

 and spatulate-obovate to pinnately parted into narrow linear lobes: heads 

 8-20-flowered, slender-peduncled ; involucre of 8-10 linear-lanceolate, gradu- 

 ally acuminate principal bracts: bristles of pappus several times longer than 

 the oblong scale at the base. Microseris nutans. From British Columbia 

 and Montana to southwestern Colorado and California. 



98. MALACOTHRIX DC. 



Leafy-stemmed or sometimes scapose herbs, with alternate or all radical 

 leaves and long-peduncled panicled or solitary heads of yellow or white 

 flowers that are usually nodding in the bud. Involucre many-flowered, the 

 bracts either imbricated or only calyculate. Receptacle with or without deli- 

 cate capillary bristles among the flowers. Achenes not flattened, short-oblong 

 or columnar, glabrous, terete and striately 5-15-costate, or 4-5-angled by 

 the prominence of the stronger ribs, slightly if at all narrowed either way, 

 with broad truncate apex having an entire or denticulate border or sharp edge. 

 Pappus a series of soft and scabrous, or near the base barbellulate bristles, 

 which are deciduous more or less in connection, and commonly 1-8 outer and 

 stouter ones which are more persistent and smoother. 



The outer pappus of 2-8 persistent bristles . . . . . . 1. M. Torreyi. 



The pappus a single series and all deciduous. 



Summit of achene bordered by 15 minute teeth . . . . .2. M. sonchoides. 



Summit of achene cupulate but entire . . . . . . 3. M. Fendleri. 



1. Malacothrix Torreyi Gray, Proc. Am. Acad. 9: 213. 1874. Stems 1-3 

 dm. high, from an annual root, branching from the base: lower leaves oblong, 

 rather short, pinnatifid with short and dentate lobes, teeth and lobes callous- 

 mucronate: heads seldom less than 12 mm. high, broadish-campanulate, short- 

 peduncled on the leafy branches ; bracts of the involucre lanceolate, acuminate : 

 achenes linear-oblong, 5-angled by as many salient often almost wing-like ribs, 

 a much less prominent pair in each interval: outer pappus of 2-8 stout per- 

 sistent bristles, between the thickish bases of which are minute teeth. 

 Southeastern Oregon to Nevada and Utah. 



2. Malacothrix sonchoides (Nutt.) T. & G. Fl. 2: 486. 1843. Stem freely 

 branching, the branches ascending and sparsely leafy except near the base; 

 herbage glabrous or early glabrate: leaves oblong or the upper narrowly 

 lanceolate, pinnatifid with short callous-toothed lobes: peduncles 3 cm. or less 

 long: involucre about 8 mm. high; the bracts linear-acuminate: ligules bright 

 yellow, a full cm. long: achenes 15-striate, 5 of the ribs stronger than the 

 others, rendering the achene somewhat 5-anglcd, crowned with a 15-denticulate 

 white border; permanent pappus-bristles none. (M. runcinata A. Nels. Bull. 

 Torr. Bot. Club 26: 4S5. 1899.) From Wyoming and Colorado to California. 



3. Malacothrix Fendleri Gray, PI. Wright. 2: 104. 1852. Low, glabrate; 

 stems from a slender root, few or several, diffuse: earliest loaves sparsely 

 arachnoid; the radical runcinute-pinnatifid, the teeth and lobes cuspidate- 

 mucronate; the cauline few, linear, the uppermost entire: achenes cylindrical, 

 equally 15-costate the summit bordered by a cupulate crown, white within 

 and with entire margin; all the pappus deciduous or rarely with 1 or 2 per- 

 sistent bristles. New Mexico and westward. 



