Astragalus hidalgensis var. protensus

Title

Astragalus hidalgensis var. protensus

Authors

Rupert C. Barneby

Scientific Name

Astragalus hidalgensis var. protensus Barneby

Description

25b. Astragalus hidalgensis var. protensus

Stems sparingly branched below, spurred at one or more nodes preceding the first peduncle, floriferous upward from near or above the middle; peduncles 6-9.5 cm. long, greatly surpassing the leaf; calyx 4-4.5 mm. long, its tube ± 2.6 mm., its teeth subulate, 1.3-1.8 mm. long; otherwise as given in the key.—Collections: 1 (o).

Mountain ravines, probably in open woodland, ± 4500 feet, known only from Jacala, Hidalgo.—Map No. 8.—June to July, probably later.

Astragalus hidalgensis var. protensus (drawn out, of the racemes and pods), var. nov., a var. hidalgensi pedunculis racemisque elongatis et legumine longiori et angustiori 14-18- ovulato absimilis.—Hidalgo: Jacala, 4500 ft., June 26, 1939, fl. & fr., Virginius H. Chase 7160.—Holotypus, NY! isotypi, ARIZ, GH, MICH, MO!

It seems possible but hardly probable that the collection described above as var. protensus represents only an aberrant form of A. hidalgensis, for it differs so greatly in facies because of the loosening and lengthening of so many organs: stipules, peduncles, axis of the racemes, calyx-teeth, and finally the pod, which is narrowly oblong-ellipsoid rather than obliquely obovoid as in var. hidalgensis and contains seven to nine rather than only four or five pairs of ovules. The varieties of the Hidalgo milk-vetch are obviously too little known, and since they are nearly sympatric may prove to run together in nature. Field observation is required to settle their status.