740 MISC. PUBLICATION 4 2 3, U. S. DEPT. OF AGRICULTURE 



106. BORAGINACEAE Borage family 



Contributed by I. M. Johnston 



Plants herbaceous or shrubby, usually bristly; leaves simple, pre- 

 vailingly alternate; flowers perfect, regular, solitary or cymose; cymes 

 glomerate-racemose or spicate, frequently unilateral and coiled 

 (scorpioid), usually with bracts between, to one side of, or opposite 

 the flowers; calyx usually deeply lobed, somewhat irregular; corolla 

 5-lobed, commonly with folds or saccate-intruded appendages in the 

 throat; stamens 5, borne on the corolla tube alternate with the lobes; 

 ovary superior, bicarpellate, usually 4-ovulate, entire or lobed, be- 

 coming tough or bony at maturity; fruit commonly breaking up into 

 4 single-seeded lobes (nutlets) ; style lobed or entire, seated in the peri- 

 carp at the apex of the fruit or borne between the fruit lobes (nutlets) 

 on the receptacle, or on an upward prolongation thereof (gynobase) ; 

 endosperm absent or scarce. 



The classification of this family is based primarily upon the structure 

 of the fruit. In many cases it is very difficult to recognize the genus 

 and almost impossible to obtain a precise identification of the species, 

 if the specimens lack mature fruiting structures. 



The Boraginaceae are of small importance economically, but the 

 family comprises numerous species that are cultivated as ornamentals, 

 notably in the genera Heliotropium (heliotrope), Anchusa, Echium, 

 and Myosotis (forget-me-not). 



Key to the genera 



1. Style 2-cleft; stigmas 2, distinct; flowers solitary or clustered in the stem 



forks 1. Coldenia. 



1. Style simple; stigmas united (2). 



2. Style springing from the pericarp at apex of the fruit, falling away with the 

 nutlets; stigma annulate, usually surmounted by a sterile conic or cylindric 



appendage; corolla plaited in the bud 2. Heliotroptum. 



2. Style borne between the lobes of the fruit (i. e., the nutlets), and attached to 



the receptacle or gynobase; stigma capitate, unappendaged; corolla not 



plaited (3). 



3. Mature calyx very irregular, burlike, 3 of the lobes nearly distinct, the 



others more united and enclosing the fruit, becoming cornute with 7 



to 9 coarse barbed appendages; ovules 2 3. Harpagonella. 



3. Mature calyx usually regular or practically so, not armed with hornlike 

 barbed appendages; ovules usually 4 (4) . 

 4. Nutlets stellately spreading, attached at the apical (radicle) end, armed 

 with hooked appendages; small slender annuals, 4. Pectocarya. 

 4. Nutlets erect, incurved, or weakly divergent, attached at or below the 

 middle, i. e., toward the cotyledon end (5). 

 5. Margin of the nutlets with barbed appendages (6). 



6. Plant annual; pedicels erect; style surpassing the nutlets. 



5. Lappula. 



6. Plant perennial or biennial; pedicels reflexed; style surpassed by 



the nutlets 6. Hackelia. 



5. Margin of the nutlets lacking barbed appendages (7). 



7. Corolla blue, clearly differentiated into a tube, throat, and lobes. 



7. Mertensia. 

 7. Corolla white or yellow, the throat not conspicuously differentiated 

 from the tube and lobes (8). 

 8. Nutlets attached above the base along a usually open and gen- 

 erally basally forked ventral groove or slit, or by a triangular 

 opening in the pericarp 8. "Cryptantha. 



