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Description of several New or Rare Plants which have lately 

 Flowered in the Neighbourhood of Edinburgh, chiejly in the 

 Royal Botanic Garden. By Dr Graham, Prof, of Botany.* 



Acacia tristis. 



A. tristis; stipulis setaceo-spinescentibus, deciduis; phyllodiis luridis, 

 falcatis, nervis duobus inaequalibus, margine superiore recurvo ; pe- 

 dunculis subsolitariis, cumque folio longiore, ramuloque sulcato, pu- 

 berulis. 



Acacia tristis, Grah. Bot. Mag. t. 3. 420. 



Deschiption Shrub erect; branches drooping, puberulent, many-fur- 

 rowed, when young green, afterwards brown. Stipules like strong rigid 

 straight and spreading set£E, which are at first green and flattened on the 

 sides which are towards the phyllodium, soon becoming brown, and at 

 last falling, lateral and free at the base. Phyllodia very shortly petioled, 

 suberect, dark green, slightly falcate, curving upwards except at the mu- 

 cronated tip, which is more or less bent down, slightly pubescent, espe- 

 cially when young, undulate, having a single sessile gland on the upper 

 edge near the base ; middle rib tolerably conspicuous, branching upon its 

 lower side ; a fainter subsimple rib occurs between this and the upper 

 edge, and rather more than halfway to this last. Capitula solitary or 

 very rarely in pairs, on solitary pubescent peduncles half the length of 

 the phyllodium, and rising from the side of the bud in its axil ; many- 

 flowered, flowers yellow. Bractece greatly attenuated at the base, shortly 

 so at the apex, marcescent. Calyx turbinate, 5-toothed, teeth rounded 

 and ciliated. Corolla twice the length of the calyx, unequally 5-cleft, 

 segments narrow. Stamens very numerous, twice as long as the corolla. 

 Style lateral, longer than the stamens. Germen oblong, slightly com- 

 pressed, yellowish-green. 

 This plant was raised at the Royal Botanic Garden, Edinburgh, from 

 seeds communicated by the late Mr Fraser from New Holland, in 1828, 

 and flowered in the greenhouse in March 1835. Its nearest affinity is 

 to A. undulatay "Willd., but may be easily distinguished from this by its 

 lurid not lively green colour, by its phyllodia being longer, actually and 

 relatively to the peduncle, by their peculiar nervation, by its more seta- 

 ceous stipules, which are lateral, not inferior, and distinct, not coalescent 

 at the base, by its capitula being generally single, very rarely in pairs, 

 the reverse of what is observed in A. unduiata, in which also the flowers 

 are larger, with much more acuminated bracteae. 

 It is also, and perhaps quite as nearly, allied to A. armata^ from which it 

 is distinguished by the smaller degree of hairiness of the branches, by 

 the pubescent peduncles shorter than the phyllodia, and by the nervation 

 of these. In the arrangement of the species, it ought to stand between 

 A. undulata and A. armata. 

 In the present state of our knowledge, these characters must be admitted 

 as specific distinctions, but it is not at all improbable that we shall here- 

 after be found to have very unduly multiplied species in this genus. In 

 other genera, forms far more unlike than many of these are to each other, 

 are known from their history in cultivation to be hybrids, or seedling 

 varieties. The Acacias are seldom raised from the seeds of cultivated 

 plants ; and we have but an imperfect assurance that, in the wild state, 

 they have not that mutability of form which occurs in other genera, and 

 renders specific distinctions uncertain. These observations are parti- 

 cularly forced upon me by the remarkable varieties of form which exist 

 among the different specimens of Acacia dccipinis, A. longifolia^ A. stricta^ 



* The greater number of the following descriptions were put In types several months »gp, but 

 from the crowded sUte of the Journal, the publication has been suspended till now. 



