14 



Lomatium attenuatum Evert 

 Tapertip Biscuitroot 



A. DESCRIPTION 



1. General description: This is a yellow flowered member of 

 the Apiaceae (carrot family). The plants are relatively 

 small and are low growing from a fleshy taproot. The leaves 

 are finely dissected, like lace, and have a petiole which 

 sheaths the stem. The small flowers are borne in a compound 

 inflorescence, called an umbel, with the umbelets (little 

 umbels) having series of inconspicuous bracts below them. 

 The flower parts are in groups of five except for the ovary, 

 which is divided in two. The two parted fruits, called 

 schizocarps, are flattened parallel to the suture and have 

 low ribs on their faces. An illustration of the species is 

 included in Appendix E. 



. 2. Technical species description (quoted from Evert 1983): 

 Plant perennial, short-caulescent, with only one or two 

 cauline leaves, more or less scaberulous, (7-) 10-25 cm tall, 

 from an elongated thickened taproot and also occasionally 

 from a several-branched caudex; leaves petiolate, 3-pinnate 

 or ternately 3-pinnate, blades 2.0-11 cm long, 1.5-10 cm 

 wide, ovate in outline, the ultimate divisions linear to 

 oblanceolate, 2-5 mm long, 0.5-1.5 mm wide, obtuse to 

 somewhat acute and mucronate; petioles 1.5-5 cm long, the 

 dilated and scarious sheathing extending to the middle or 

 above; peduncles 1-3(4), scaberulous, exceeding the leaves 

 in fruit, 10-15 cm long; involucre usually absent but 

 occasionally 1 inconspicuous, filiform bract present; 

 fertile rays 5-8, spreading, angled, unequal, (1.5)3-5 cm 

 long in fruit; sterile rays 4-8 spreading, 3-10 mm long in 

 fruit; involucel absent or of 1-6 inconspicuous linear- 

 lanceolate, attenuate, non-connate bractlets, 1-4 mm long; 

 umbellets ca. 15-flowered, only 2-6 developing into fruit; 

 pedicels 3-10 mm long in fruit; petals 1.5 mm long including 

 the incurved apex, yellow, obovate, glabrous; styles 1-1.5 

 mm long, spreading or reflexed; ovaries glabrous to slightly 

 scaberulous; fruit oblong-elliptic, glabrous, glossy, 5-8 mm 

 long, 3-5 mm wide, the wings ca. 0.5-0.75 mm wide, narrower 

 than the body; oil tubes prominent, 1 in each interval, 2 on 

 the commissure; carpophore bipartite. 



3. Diagnostic characters: Lomatium attenuatum differs from 



Lomatium cous, which it resembles in habit, leaf dissection, 

 and fruit characters, by having a less conspicuous involucel 

 with tapered rather than rounded bracts and greater overall 

 scabrosity (Evert 1983). Both species are found in 

 Beaverhead County, but they have not been observed growing 

 together at the same site. 



