36 MISC. PUBLICATION 110, U. S. DEPT. OF AGRICULTURE 



mately the second stage in the tran- 

 sition from herbs to shrubs, of 

 which the first is suffrutescence. 



Sulcate: Grooved, especially if the 

 groove (sulcus) or furrow is deep 

 and longitudinal, as the sulcate 

 stone in the fruit of flowering dog- 

 wood or the sulcate pod of sheep 

 loco {Astragalus nothoxys). 



Super-: A prefix (Latin) signifying 

 above, beyond, surpassing, and the 

 like. For example, superlabial 

 means above a lip, and superfoliar 

 refers to a region or object above 

 the foliage. 



Superior: Lying above another organ 

 or part ; said especially of an ovary 

 when the calyx and stamens are 

 free from it and attached below it. 

 Epigynous stamens are sometimes 

 called superior, because growing 

 from (adnate to) the top of the 

 ovary. 



Supra-: A prefix (Latin) signifying 

 over, ' above, or beyond, where 

 growth or action is implied. For 

 example, " supracrescent " signifies 

 " growing over " another part or or- 

 gan. 



Suture: A seam, raphe, or seamlike 

 ridged or furrowed medial line ; a 

 line of splitting or dehiscence. The 

 sutures of a pod are the lines where 

 the valves of the pod separate to 

 discharge the seeds. 



Symbiosis: The living together of dis- 

 similar organisms; especially (as 

 opposed to parasitism) when the re- 

 lationship is mutually beneficial. 

 As, for example, the alga and fungus 

 which compose a lichen ; the nitro- 

 gen-fixing bacteria on the roots of 

 an aif alfa or clover plant ; or the 

 yucca moths {Pronuba spp.) and 

 species of Yucca. 



Symbiotic: Of or pertaining to sym- 

 biosis, as the symbiotic mycorrhizas 

 of an oak or orchid root. 



Sympetalous: Having the petals more 

 or less united. The same as gamo- 

 petalous. 



Syn.: Synoptic (al) ; synonym. 



Synonym: A different botanical name 

 for the same plant ; an untenable 

 specific or generic name. For ex- 

 ample, Abies menziesii is a synonym 

 of Picea sitchensis (Sitka spruce), 

 Abies being wrong generically for 

 this tree and the specific name men- 

 ziesii later than sitchensis, which is 

 unpreoccupied and properly pub- 

 lished. There are two main divi- 

 sions of synonyms: (1) Typonyms, 

 or absolute synonyms, and which are 

 admittedly based on the same con- 

 cept or type; (2) those whose iden- 



tity is a matter of individual taxo- 

 nomic opinion. To the latter cate- 

 gory belong segregated genera and 

 species about whose integration with 

 other genera and species there can 

 never be universal uniformity of 

 opinion among botanists. 



Systematic botany: See taxonomy. 



Taxonomy: The science of classifica- 

 tion. In botany synonymous with 

 systematic botany, which is the clas- 

 sification or arrangement of plants 

 according to their natural relation- 

 ships and the principles underlying 

 such classification. 



-taxy (or -taxis) : A suffix (Greek) 

 signifying arrangement, as phyllo- 

 tax'y, the arrangement of leaves on 

 a stem. 



Tegule: One of the (often sepallike) 

 involucral bracts subtending the 

 flower head of a composite (a term 

 introduced by the late C. V. Piper, 

 of the United States Department of 

 Agriculture). Same as phyllary. 



Tendril: A slender, modified branch, 

 commonly spirally coiling at the tip, 

 and serving as an organ of support, 

 as in clematis, cucurbits, grapes, pea 

 vines, and vetches. 



Terete: Elongated and round in cross 

 section; cylindrical, except that 

 terete may also be tapered. 



Ternate: Arranged in threes. 



Test.: By witness, statement, or au- 

 thority of (Latin, teste) ; same as 

 fide. 



Tetra-: A prefix (Greek) signifying 

 four. 



Tetradynamous : Having six stamens, 

 four of them longer than the other 

 two (literally, four having the pre- 

 dominance) ; a term introduced by 

 Linnaeus. The flowers of crucifers 

 (members of the mustard family) 

 are tetradynamous. 



Tetramerous: Having the parts in 

 fours. 



Thallus: An often flattened, vegetative 

 organ or body of a plant not differ- 

 entiated into stem and leaf; the 

 main body of such plants as duck- 

 weeds, lichens, and liverworts. 



Thorn: A hard, sharp-pointed plant 

 emergence, more deeply seated than 

 a prickle. A thorn is a more or 

 less vascular (thus differing from 

 spine), relatively short, modified 

 branch or twig, produced from a 

 bud. Familiar examples are seen in 

 the case of hawthorns (Crataegus 

 spp.). 



Thyrse, or Thyrsus: A more or less 

 compact or contracted, oblong to 

 ovoid-pyramidal, usually densely 

 flowered panicle, differing from a 



